2. Lithomitra acephala, Bütschli.

Shell nearly cylindrical, smooth, thick-walled, with twelve to sixteen subequal joints. On each joint a single row of small circular pores. No external strictures. Scarcely differing from the preceding species; the joints are broader and shorter, the cephalis is larger (by union of some joints?), and the ribs of the surface less distinct.

Dimensions.—Length of the shell (with twelve joints) 0.1; length of each joint 0.006 to 0.009, breadth 0.04.

Habitat.—Fossil in Barbados.

3. Lithomitra lineata, Haeckel.

Shell subcylindrical, smooth, with longitudinal ribs, and four to eight slight transverse strictures. Cephalis small, subspherical, with few small pores. Thorax broader, with two or three transverse rows of pores. Each succeeding (abdominal) joint with a single transverse row of small pores. Variable and nearly related to the two preceding species (compare my Monograph, loc. cit.).

Dimensions.—Length of the shell (with six to eight joints) 0.06 to 0.08; length of each joint (on an average) 0.01, breadth 0.03.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, in various depths; many stations; fossil in Secondary and Tertiary rocks of many places.

4. Lithomitra nodosaria, n. sp. (Pl. 79, fig. 1).

Shell subcylindrical, with longitudinal ribs, and five to eight transverse strictures, and prominent girdles between them. On each girdle (at the lowermost edge of each joint) a single transverse row of circular pores. The three or four uppermost joints are united, and represent a conical cephalis.

Dimensions.—Length of the shell (with six joints) 0.1; length of each joint 0.01 to 0.15, breadth 0.04 to 0.06.

Habitat.—Central Pacific, Station 263 to 274, depth 2350 to 2925 fathoms.

5. Lithomitra eruca, n. sp. (Pl. 79, fig. 3).

Shell subcylindrical, diminishing slightly towards both ends, with ten to fifteen slight strictures. On each joint a single transverse row of circular pores, descending obliquely in the wall. The two or three first joints form together a roundish cephalis. Usually each joint is three times as broad as long.

Dimensions.—Length of the shell (with twelve joints) 0.2; length of each joint (on an average) 0.016, breadth 0.05.

Habitat.—Central Pacific, Station 265 to 268, depth 2700 to 2900 fathoms; fossil in Barbados.

6. Lithomitra chrysalis, n. sp. (Pl. 79, fig. 4).

Shell subcylindrical, diminishing slightly towards both ends, with elegant longitudinal ribs, and with five to eight slight strictures. Each of the upper joints with two (or sometimes three) transverse rows of small pores; each of the lower joints with only a single row.

Dimensions.—Length of the shell (with six joints) 0.11; length of each joint 0.01 to 0.015, breadth 0.04 to 0.05.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

Subgenus 2. Lithomitrissa, Haeckel.

Definition.—All (or the majority) of the joints of the shell with several transverse rows of pores, in variable number.

7. Lithomitra cylindrica, n. sp.

Shell cylindrical, smooth, with twelve to sixteen internal septal rings (without external strictures). On each joint two transverse rows of small, regular, circular pores. The hemispherical cephalis also has two rows of pores. Each joint is twice as broad as long.

Dimensions.—Length of the shell (with sixteen joints) 0.3; length of each joint 0.02, breadth 0.04.

Habitat.—South Pacific, Station 297, depth 1775 fathoms.

8. Lithomitra costata, Haeckel.

Shell with longitudinal ribs, in the upper half conical, in the lower half cylindrical, with six to eight slight strictures. Small, circular pores in regular transverse rows; three rows in each upper joint, two rows in each lower joint (the last joints sometimes confluent).

Dimensions.—Length of the shell (with eight joints) 0.15; length of each joint 0.017 to 0.023, breadth 0.04 to 0.05.

Habitat.—Fossil in Tertiary rocks of Sicily; Grotte (Stöhr), Caltanisetta (Haeckel).

9. Lithomitra punctata, Haeckel.

Shell subcylindrical, smooth, with four to six distinct strictures. Cephalis small, subspherical. Thorax campanulate-conical. Abdomen cylindrical, with three to four equal joints. In each joint five to six transverse rows of small, circular pores, quincuncially disposed.

Dimensions.—Length of the shell (with five joints) 0.1; length of each joint (except the first) 0.02, breadth 0.05.

Habitat.—Fossil in Tertiary rocks of Sicily; Caltanisetta (Ehrenberg), Grotte (Stöhr).

10. Lithomitra seriolata, Haeckel.

Shell subcylindrical, smooth, with four to six sharp strictures. Cephalis small, hemispherical. Thorax conical. Abdomen cylindrical, with three to five different joints of alternate sizes. Small circular pores in transverse rows; three or four rows in the third and fifth joints, seven or eight rows in the second, fourth, and sixth joints.

Dimensions.—Length of the shell (with six joints) 0.1; length of the second and fourth joints 0.03, of the third and fifth joints 0.015.

Habitat.—Mediterranean, Crete (Ehrenberg), Corfu (Haeckel).

11. Lithomitra hyperborea, Haeckel.

Shell cylindrical, with prominent longitudinal ribs and six deep strictures. Cephalis hemispherical. On each joint three to four transverse rows of small, obsolete pores. Each joint is about twice as broad as long.

Dimensions.—Length of the shell (with six joints) 0.12; length of each joint 0.02, breadth 0.04.

Habitat.—Arctic and Northern Pacific, Kamtschatka (Bailey).

12. Lithomitra australis, Haeckel.

Shell subcylindrical, smooth, with five deep strictures. The two middle joints somewhat larger than the two proximal and the two distal joints. Pores small, circular, in regular, transverse rows; two rows in the first and the sixth joints, five rows in the second and the fifth, seven or eight rows in the third and fourth joints. The two latter are twice as broad as long.

Dimensions.—Length of the shell (with six joints) 0.14; length of the four smaller joints 0.017, of the two larger joints 0.035; breadth 0.06.

Habitat.—Antarctic Sea (lat. 78° 10′ S., long. 162° W.) Ross.

13. Lithomitra eminens, Haeckel.

Shell subcylindrical, rough, with seven slight strictures. The two or three middle joints half as long as the two preceding and the two following joints. Cephalis small, subspherical. Pores small, in subregular, transverse rows, on the fifth and sixth joints only two rows, on the second, third, seventh, and eighth joints four to five rows.

Dimensions.—Length of the shell (with eight joints) 0.27; length of the fifth and sixth joints 0.17, of the others 0.03 to 0.04; breadth 0.08.

Habitat.—Fossil in Tertiary rocks of Sicily, Grotte (Stöhr).

14. Lithomitra infundibulum, n. sp. (Pl. 79, fig. 5).

Shell in the upper half subconical, in the lower half subcylindrical, rough, with four slight strictures. Cephalis hemispherical. Thorax conical. Abdomen subcylindrical, three-jointed. Pores of the second, third, and fourth joints funnel-shaped, with very small inner, and larger double-contoured outer aperture; on the thorax twelve transverse rows, on the third and fourth joints five rows. Fifth joint with irregular, polygonal pores.

Dimensions.—Length of the shell (with five joints) 0.2; length of the thorax 0.06, breadth 0.08; length of each abdominal joint 0.04, breadth 0.08.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

Genus 647. Eucyrtidium,^[264] Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54.

Definition.—Stichocorida (vel Stichocyrtida eradiate aperta) with ovate or spindle-shaped shell, the mouth of which is constricted, but not prolonged into a tube. Cephalis with a solid horn.

The genus Eucyrtidium (as here stated in the definition) and the three following nearly allied genera differ from the preceding Stichocorida in the more or less constricted mouth, and the consequent ovate or spindle-form of the multiarticulate shell. The middle joints of the latter are broader than the upper and the lower joints. In the earlier definition given in my Monograph (1862, pp. 312 to 320), the genus had a much wider sense; but the very large number of species since detected requires a more strict definition. Ehrenberg confounded in his genus Eucyrtidium a large number of very different Cyrtoidea. In his last works (1872, 1875) he described not less than one hundred and eleven species, fifty-five fossil and fifty-six living (eight fossil species being yet living). But, in reality, these one hundred and three species belong to twenty or twenty-two very different genera of Cyrtoidea.

Subgenus 1. Eucyrtis, Haeckel, 1881, Prodromus, p. 438.

Definition.—All joints of the shell nearly of the same length (excepting often the first). Surface smooth or rough, without spines.

1. Eucyrtidium acuminatum, Ehrenberg.

Shell smooth, slender, nearly spindle-shaped, without external strictures, but with eight to nine internal septal rings. All joints (except the first) nearly of the same length (or the upper somewhat longer). The fifth joint is the broadest. Cephalis small, subspherical, with a short, conical horn. Pores very small and numerous, regular, hexagonal, four to six on the length of each joint.

Dimensions.—Length of the shell (with eight joints) 0.14; length of each joint about 0.02; greatest breadth, in the fifth joint, 0.07.

Habitat.—Fossil in Tertiary rocks of Sicily (Caltanisetta, Grotte, &c.).

2. Eucyrtidium tropezianum, Haeckel.

Shell smooth, slender, nearly spindle-shaped, without external strictures, but with seven or eight internal septal rings. All joints of the same length. The fifth and sixth joints are the broadest. Cephalis hemispherical, with a pyramidal horn of the same length. Pores very small and numerous, regular, circular, hexagonally framed, five to six in the length of each joint. (Very near to the preceding species, but more regular, and with different pores.)

Dimensions.—Length of the shell (with eight joints) 0.16, length of each joint 0.02; greatest breadth (in the fifth joint) 0.07.

Habitat.—Mediterranean, French shore, St. Tropez (J. Müller), surface.

3. Eucyrtidium hexagonatum, n. sp. (Pl. 80, fig. 11).

Shell smooth, ovate, with six to seven internal septal rings. All joints (except the first) nearly of the same length; the sixth joint is the broadest. The seventh and eighth joints (broken off in the specimen figured) gradually decrease toward the constricted mouth, which is as broad as the septum between the third and fourth joints. Cephalis and thorax together pear-shaped, with circular pores, sharp lumbar stricture, and a stout, pyramidal horn of the same length. The five or six abdominal joints with regular, hexagonal pores, six or seven in course of the length of each joint.

Dimensions.—Length of the shell (with eight joints) 0.2, length of each joint 0.025 to 0.03; greatest breadth (in the sixth joint) 0.1.

Habitat.—Central Pacific, Stations 266 to 272, depth 2425 to 2925 fathoms.

4. Eucyrtidium fusiforme, n. sp.

Shell smooth, slender, spindle-shaped, without external strictures, but with ten to twelve internal septal rings. All joints of the same length; the sixth joint is the broadest. Cephalis conical, with a pyramidal horn of the same length. Pores regular, circular, four or five in course of the length of each joint. (Differs from all other species of the genus in the regular, slender, spindle form; the constricted mouth of the last joint is half as broad as the sixth joint.)

Dimensions.—Length of the shell (with twelve joints) 0.24, length of each joint 0.02; greatest breadth (on the sixth joint) 0.06, of the mouth 0.03.

Habitat.—Indian Ocean, Maldive Islands (Haeckel, 1882), surface.

5. Eucyrtidium doliolum, n. sp.

Shell smooth, barrel-shaped, or nearly spindle-shaped, with eight or nine distinct strictures. All joints (except the first) of the same length; the fourth joint is the broadest. Cephalis small, subspherical, with two short, divergent, conical horns. Pores regular, circular, hexagonally framed, three to four in course of the length of each joint.

Dimensions.—Length of the shell (with ten joints) 0.2, length of each joint 0.022; greatest breadth (in the fourth joint) 0.08.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms.

Subgenus 2. Stichocyrtis, Haeckel, 1881, Prodromus, p. 438.

Definition.—All joints of the shell nearly of the same length (excepting often the first). Surface spiny.

6. Eucyrtidium spinosum, n. sp.

Shell spiny, slender, ovate, without external strictures, but with seven or eight internal septal rings. Conical spines of different lengths are scattered over the whole surface. All joints have nearly the same length; the sixth is the broadest. Cephalis conical, with one large and two or three smaller conical horns. Mouth constricted, half as broad as the shell. Pores irregular, roundish, double-edged, three to four on the length of each joint.

Dimensions.—Length of the shell (with eight joints) 0.16, length of each joint 0.02; greatest breadth (on the sixth joint) 0.06.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

7. Eucyrtidium chrysalidium, n. sp.

Shell spiny, spindle-shaped, with four to five slight strictures, above each stricture a circle or girdle of conical spines (as in the similar Cyrtophormis cingulata, Pl. 78, fig. 18). All joints (except the first) have the same length. Cephalis subspherical, with a bunch of divergent spines. Mouth constricted, only one-third as broad as the third joint, which is the broadest. Pores subregular, circular, four to five on the length of each joint.

Dimensions.—Length of the shell (with six joints) 0.18, length of each joint 0.032; greatest breadth 0.08.

Habitat.—South Pacific, Station 302, depth 1450 fathoms.

Subgenus 3. Artocyrtis, Haeckel.

Definition.—Joints of the shell of very different lengths. Surface smooth or rough, without spines.

8. Eucyrtidium profundissimum, Ehrenberg.

Shell smooth, campanulate, ovate, with three internal septal rings. Four joints of different lengths. Cephalis subspherical, with a small bristle-shaped horn. Thorax campanulate, nearly twice as long as each of the two following joints, which are nearly equal in breadth. Terminal mouth wide open, little constricted. Pores very small and numerous, regular, hexagonal.

Dimensions.—Length of the shell (with four joints) 0.12; length of the thorax 0.05, breadth 0.07.

Habitat.—Pacific; many Stations (Stations 206, 225, 253, 265, &c.), in depths between 2000 and 4000 fathoms.

9. Eucyrtidium anthophorum, Haeckel.

Shell smooth, slender, ovate, with three slight strictures. Four joints of different lengths. Cephalis subspherical, with a stout, club-shaped, spinulate or branched horn of the same length. Second campanulate and third subcylindrical joint about equal in size. Fourth joint only half as long, with slightly constricted mouth (broken off in Ehrenberg's figure). Pores small and numerous, regular, circular, quincuncial.

Dimensions.—Length of the shell (with four joints) 0.12; length of the second and of the third joints 0.04, breadth 0.05 to 0.06.

Habitat.—Fossil in Barbados.

10. Eucyrtidium hertwigii, n. sp. (Pl. 80, fig. 12).

Shell smooth, ovate, truncate, with three distinct strictures. Four joints of different lengths. Cephalis campanulate, with an internal rod-cross, and a stout pyramidal horn of the same length. Second joint campanulate. Third joint larger, subcylindrical, with a variable number of irregular, longitudinal ribs, some of which are prolonged into the second and fourth joints. The latter is only half as long, and slightly constricted towards the mouth. Pores small and numerous, subregular, circular.

Dimensions.—Length of the shell (with four joints) 0.22. Length of the single joints, a 0.03, b 0.06, c 0.08, d 0.05; breadth, a 0.03, b 0.1, c 0.12, d 0.11.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

11. Eucyrtidium lagena, Haeckel.

Shell smooth, bottle-shaped, with three distinct strictures. Four joints of different sizes. Cephalis small, spherical, with a bristle-shaped horn of the same length. Second joint conical, third subcylindrical, fourth inflated, with slightly constricted mouth; their lengths about equal. Pores subregular, hexagonal, large, with thin bars.

Dimensions.—Length of the shell (with four joints) 0.16; length of each of the three lower joints about 0.05, breadth 0.05 to 0.064.

Habitat.—Mediterranean (Messina).

12. Eucyrtidium teuscheri, n. sp. (Pl. 77, fig. 5).

Shell smooth, bottle-shaped, with three distinct strictures. Four joints of different lengths. The third joint four times as long as each of the two first joints, and longer than the fourth, which is little constricted towards the mouth. The greatest breadth is in the middle of the shell. Cephalis hemispherical, with a small, conical horn of the same length. Pores large, circular, of variable sizes. Dedicated to Dr. Reinhold Teuscher.

Dimensions.—Length of the shell (with four joints) 0.16. Length of the single joints, a 0.015, b 0.02, c 0.07, d 0.055; breadth, a 0.03, b 0.05, c 0.08, d 0.06.

Habitat.—Central Pacific, Stations 266 to 274, depth 2350 to 2925 fathoms.

13. Eucyrtidium bütschlii, n. sp. (Pl. 77, fig. 7).

Shell rough, slender, ovate, truncate, with three distinct strictures. Four joints of different lengths; the third is the largest, inflated, subspherical. Fourth joint subcylindrical, little constricted towards the truncate mouth. Cephalis hemispherical, with a small, conical horn. Pores circular, much larger in the third joint than in the three others.

Dimensions.—Length of the shell (with four joints) 0.16. Length of the single joints, a 0.02, b 0.03, c 0.06, d 0.05; breadth, a 0.03, b 0.07, c 0.09, d 0.07.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

14. Eucyrtidium galatheæ, Ehrenberg.

Shell smooth, campanulate, with three deep strictures. Four joints of different lengths; the fourth joint is the broadest, twice as long as the third and the second, three times as long as the hemispherical cephalis, which bears a stout, pyramidal, oblique horn of twice the length. Mouth little constricted. Pores regular, circular, in transverse rows, three rows in each of the three first joints, five or six rows in the last joint.

Dimensions.—Length of the shell (with four joints) 0.12; length of the fourth joint 0.05, breadth 0.07.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.

15. Eucyrtidium galea, Haeckel.

Shell smooth, helmet-shaped, with four sharp strictures. Five joints of different lengths. Cephalis small, spherical, with a thin pyramidal horn of the same length. Second joint conical, about as long as the third, longer than the fourth and the fifth joints. The third joint is the broadest. Pores regular, circular, small and numerous.

Dimensions.—Length of the shell (with five joints) 0.18; length of the second and the third joints 0.05, of the fourth 0.03; breadth 0.08 to 0.1.

Habitat.—Mediterranean (Messina), surface.

16. Eucyrtidium eruca, Ehrenberg.

Shell smooth, slender, ovate, or nearly spindle-shaped, with four sharp strictures. Five joints of different lengths, the third and fourth nearly equal, twice as long as the fifth, one and a half times as long as the second; the fourth joint is the broadest. Mouth little constricted. Cephalis subspherical, with a small, conical horn. Pores small and numerous, subregular, circular.

Dimensions.—Length of the shell (with five joints) 0.12 to 0.14; length of the third and the fourth joints, 0.03 to 0.04, breadth 0.04 to 0.05.

Habitat.—Cosmopolitan; Atlantic, Pacific, in different depths; also fossil in Barbados and Sicily.

17. Eucyrtidium montiparum, Ehrenberg.

Shell rough, nearly spindle-shaped, with five deep strictures. Six joints of different lengths, the third and fourth nearly equal, longer than the fifth and the sixth joints; the fourth joint is the broadest. Mouth slightly constricted. Cephalis very small, hemispherical, hyaline, with a short, conical horn. Pores subregular, circular, twice as broad as in the similar smaller preceding species.

Dimensions.—Length of the shell (with six joints) 0.2; length of the third and the fourth joints 0.05, breadth 0.07 to 0.08.

Habitat.—Fossil in Barbados.

18. Eucyrtidium cienkowskii, n. sp. (Pl. 80, fig. 9).

Shell smooth, subconical, with five distinct strictures. Six joints of different lengths; the third joint conical, one and a half to two times as long as each of the other joints; the fifth joint is the broadest. Mouth wide, very slightly constricted. Cephalis hemispherical, with an oblique pyramidal horn of the same length. Pores regular, circular, in dense transverse rows; five to six rows in each of the three last joints, eight to nine rows in the third joint.

Dimensions.—Length of the shell (with six joints) 0.16, length of the third joint 0.04, of each following joint 0.02; greatest breadth (in the fifth joint) 0.08.

Habitat.—South Pacific, Station 295, depth 1500 fathoms.

19. Eucyrtidium elongatum, Stöhr.

Shell rough, slender, nearly spindle-shaped, variable in size and form, with six to seven distinct strictures. Seven to eight joints of different lengths, often alternately longer and shorter. The second and the last joints are the longest, the third is the broadest. Mouth slightly constricted (broken off in Stöhr's figure). Cephalis small, subspherical, with a small, oblique, curved horn. Pores irregular.

Dimensions.—Length of the shell (with seven joints) 0.2; length of the single joints, between 0.02 and 0.04, breadth 0.06 to 0.08.

Habitat.—Fossil in Sicily (Grotte, Caltanisetta).

20. Eucyrtidium stöhrii, n. sp.

Shell smooth, spindle-shaped, gradually diminishing towards both ends, with eight to ten distinct strictures. Nine to eleven joints of different lengths; the two or three middle joints—fifth, sixth, and seventh—longer and broader than the other joints; the broadest is the fifth joint, which is twice to three times as long as the first and last joints. Cephalis subspherical, with a conical horn of the same length. Terminal mouth strongly constricted, one-half or one-third as broad as the fifth joint. Pores small, regular, circular.

Dimensions.—Length of the shell (with ten joints) 0.22; length of the largest (fifth joint) 0.03, breadth 0.09.

Habitat.—Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.

21. Eucyrtidium scalarium, n. sp.

Shell smooth, slender, ovate, with nine to ten deep strictures, and ten to eleven separate step-like joints of different lengths. The sixth joint is the longest, twice as long as the fourth, and three times as long as the third and the last joint; the seventh and eighth joints are the broadest, one and a half times as broad as the wide mouth. Cephalis hemispherical, with a short pyramidal horn of the same length. Pores small and numerous, subregular, square, in regular transverse rows; six rows in the sixth joint, three rows in the last joint. (Somewhat similar to Spirocyrtis scalaris, Pl. 76, fig. 14, but ovate, not conical and not spiral.)

Dimensions.—Length of the shell (with eleven joints) 0.22, breadth 0.11; length of the last joint 0.01, of the sixth 0.03.

Habitat.—North Atlantic, Station 64, surface.

Subgenus 4. Acanthocyrtis, Haeckel, 1881, Prodromus, p. 437.

Definition.—Joints of the shell of very different lengths. Surface spiny.

22. Eucyrtidium tricinctum, n. sp. (Pl. 78, fig. 13).

Shell spiny, spindle-shaped, with three distinct strictures. Four joints of different lengths, the first and third half as long as the second and fourth; the third joint is the broadest, four times as broad as the strongly constricted mouth. Spines irregularly scattered over the lower half of the shell, increasing in size towards the mouth. Pores subregular, circular.

Dimensions.—Length of the shell (with four joints) 0.25. Length of the single joints, a 0.03, b 0.08, c 0.04, d 0.09; breadth (of the third joint) 0.1.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

23. Eucyrtidium armatum, n. sp. (Pl. 78, fig. 14).

Shell spiny, spindle-shaped, with three distinct strictures. Four joints of different lengths, the second and third joints of the same length, shorter than the fourth joint; the third joint is the broadest, four times as broad as the strongly constricted mouth. The latter, as well as the conical cephalis, is armed with an irregular bunch of strong conical spines, while numerous smaller spines are scattered over the whole surface. Pores irregular, roundish, double-contoured.

Dimensions.—Length of the shell (with four joints) 0.2. Length of the single joints, a 0.02, b 0.05, c 0.05, d 0.08; breadth (of the third joint) 0.1.

Habitat.—Western Tropical Pacific, Station 224, depth 1850 fathoms.

24. Eucyrtidium conostoma, n. sp. (Pl. 78, fig. 16).

Shell spiny, spindle-shaped, with four distinct strictures. Five joints of different lengths, having the proportion = 1 : 2 : 3 : 6 : 10. The fourth joint is the broadest, inflated, twice as broad as long. Cephalis small, with a conical horn of the same length. Fifth joint inversely conical, with a narrow mouth, broader than the cephalis. Short conical spines are scattered over the whole surface. Pores subregular, circular.

Dimensions.—Length of the shell (with five joints) 0.22. Length of the single joints, a 0.01, b 0.02, c 0.03, d 0.06, e 0.1; breadth (of the fourth joint) 0.09.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

25. Eucyrtidium ehrenbergii, n. sp. (Pl. 78, fig. 15).

Shell spiny, spindle-shaped, with four distinct strictures (the first and the fourth are by a mistake not distinctly figured). Five joints of different lengths, having the proportion = 2 : 3 : 4 : 2 : 5. The third joint is the broadest, twice as broad as long, and twice as broad as the constricted mouth. Whole surface covered with strong spines. Pores irregular, roundish.

Dimensions.—Length of the shell (with five joints) 0.16. Length of the single joints, a 0.02, b 0.03, c 0.04, d 0.02, e 0.05; breadth (in the third joint) 0.08.

Habitat.—Western Tropical Pacific, Station 220, depth 1100 fathoms.

26. Eucyrtidium ovatum, n. sp.

Shell spiny, inversely ovate, with five sharp strictures. Six joints of different lengths, having the proportion = 1 : 3 : 2 : 1 : 1 : 3. The third joint is the broadest, three times as broad as the constricted mouth. Cephalis with a stout pyramidal horn of the same length. Whole surface spiny. Pores irregular, roundish.

Dimensions.—Length of the shell (with six joints) 0.22. Length of the single joints, a 0.02, b 0.06, c 0.04, d 0.02, e 0.02, f 0.06; breadth (in the third joint) 0.11.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

Genus 648. Eusyringium,^[265] Haeckel, 1881, Prodromus, p. 437.

Definition.—Stichocorida (vel Stichocyrtida eradiata aperta) with ovate or spindle-shaped shell, the mouth of which is constricted, and prolonged into a terminal cylindrical tube. Cephalis with a solid horn.

The genus Eusyringium differs from the preceding closely allied genus Eucyrtidium in the peculiar formation of the last shell-joint, representing a narrow, cylindrical, fenestrated tube. It exhibits, therefore, to the latter the same relation as Theosyringium bears to Theocorys.

Subgenus 1. Eusyringartus, Haeckel.

Definition.—Shell with three strictures and four joints; the third joint is the largest, inflated, and much broader than the three others.

1. Eusyringium conosiphon, n. sp. (Pl. 78, fig. 10).

Shell with four joints, very thick-walled, rough. Cephalis hemispherical, with a very stout, smooth, three-sided pyramidal horn of the same length and breadth. Thorax hemispherical. Third joint subspherical, three times as long, and twice as broad as the thorax, and of the same length as the slender, inversely conical fourth joint. Pores in the three first joints subregular, circular, in the fourth joint irregular.

Dimensions.—Length of the shell (with four joints) 0.25. Length of the single joint a 0.02, b 0.03, c 0.1, d 0.1; breadth 0.12.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

2. Eusyringium pachysiphon, n. sp. (Pl. 78, fig. 11).

Shell with four joints, very thick-walled, rough. Cephalis conical, with a thick, dimpled, conical horn of the same length. Thorax hemispherical. Third joint inflated, subspherical, and fourth joint slender, inversely conical, as in the similar preceding species. Differs from the latter mainly in the form of the cephalic horn, and the cylindrical tube of the last joint. Pores subregular, circular.

Dimensions.—Length of the shell (with four joints) 0.3. Length of the single joints, a 0.03, b 0.03, c 0.12, d 0.12; breadth 0.15.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

3. Eusyringium macrosiphon, n. sp. (Pl. 78, fig. 12).

Shell with four joints, thick-walled, rough. Cephalis subspherical with a large, dimpled, conical horn of twice the length. The three following joints nearly of the same shape as in the two similar preceding species. It differs from these in the smaller size, the larger cephalic horn, and the longer tube of the fourth joint, which is twice as long as the subspherical third joint (in the figure the lower half is broken off). Pores subregular, circular.

Dimensions.—Length of the shell (with four joints) 0.3. Length of the single joints, a 0.03, b 0.03, c 0.08, d 0.16; breadth 0.09.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

4. Eusyringium leptosiphon, n. sp.

Shell with four joints, thin-walled, smooth. Cephalis subspherical, with a large, dimpled, slender, conical horn of three times the length. Thorax hemispherical. Third joint ovate, four times as long as the thorax, and of the same length as the thin, cylindrical tube of the fourth joint. Differs from the three preceding species in the more slender form and the thinness of the tube. Pores irregular, roundish.

Dimensions.—Length of the shell (with four joints) 0.33. Length of the single joints, a 0.02, b 0.03, c 0.13, d 0.15; breadth 0.1.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.

5. Eusyringium sipho, Haeckel.

Shell with four joints, thick-walled, smooth. Cephalis subspherical, hyaline, without pores, with a thick, conical horn of twice the length. Thorax hemispherical. Third joint ovate, four times as long as the thorax, and of the same length as the thin, cylindrical fourth joint. Pores subregular, circular, in the fourth joint twice as broad as in the third, and three times as broad as in the second joint.

Dimensions.—Length of the shell (with four joints) 0.22. Length of the single joints, a 0.02, b 0.02, c 0.09, d 0.09; breadth 0.08.

Habitat.—Fossil in Barbados.