This second species has also been found in the Northern United States.

This Order has been monographed recently by Janson in Abh. Ver. Brem. Bd. xii. Beilage, 1893, p. 1.

See Hudson in Month. Micr. Journ. vol. vi. 1871, pp. 121, 215, and Quart. Journ. Micr. Sci. (n.s.) xii. 1872, p. 333; Lankester, ibid. p. 338; Levander in Act. Soc. Faun. Fenn. xi. 1894.

In Denk. Ak. Wien, vol. vii. 1854, 2 Abth., p. 15. As has been suggested by Deby and by Daday, it is not impossible that Hexarthra is identical with Pedalion (and in this case the latter name, as newer, should be suppressed in favour of the former); but we must suppose that Schmarda's figure of the front view is a combination, more or less from memory or notes, of two sketches or notes taken some time before publication; the one a side view somewhat obliquely flattened, showing the two eyes as in Levander's Fig. 3; the other a front view, showing the two pairs of lateral limbs in their correct positions under pressure.

The male of Rhinops vitrea is exceptional in possessing a complete, functional alimentary canal, with mastax, stomach, and intestine (Rousselet). That of Proales werneckii has a mastax, but no intestine (Rothert).

For a full account of this group see Claus in Festschr. Z.-B. Ges. Wien, 1876, p. 75; and Plate in Mt. Stat. Neapel, vol. vii. 1886-87, p. 234; Ann. Nat. Hist. ser. 6, vol. ii., 1888, p. 86.

[Eighteen more have since been recorded.]

I have recently found a large species of this genus dwelling in the shell of the large Cladoceran Crustacean, Eurycercus lamellatus. It is remarkable for its power of completely telescoping its extremities within the middle segments, and for its immense foot-glands, both characters being doubtless correlated with its habitat. Rousselet identifies it with P. petromyzon.

Month. Micr. Journ. vol. ix. 1873, p. 287; Journ. Quekett Club, ser. 2, vol. ii. 1884-86, p. 231.

See Dr. Hudson's very suggestive presidential addresses to the Royal Microscopical Society, published in their Journal, vols. ix.-xi. 1889-91.

Euchlanis lynceus.—This is clearly not an Euchlanis, and of the six names referred to—Ploesoma, Gomphogaster, Gastropus, Gastroschiza, Bipalpus, and Dictyoderma—the first has priority, and the other five drop by the laws of zoological nomenclature.

Journ. Quekett Club, ser. 2, vol. v. 1892-94, p. 205.

Trans. Micr. Soc. (n.s.) i. 1853, p. 18 (read Dec. 31, 1851): "We may say, therefore, that the Rotifera are organized upon the plan of an Annelid larva.... I do not hesitate to draw the conclusion ... that the Rotifera are the permanent forms of Echinoderm larvae, and hold the same relation to the Echinoderms that the Hydriform Polypi hold to the Medusae, or that Appendicularia holds to the Ascidians."

Quart. Journ. Micr. Sci. (n.s.) vol. xvii. 1877, p. 399.

Ibid. (n.s.) vol. xx. 1880, p. 381.

Arb. Z. Inst. Wien, vols. i. iii. v. 1878-84; Lehrbuch der Zoologie, part iii. 1891.

Zeitschr. wiss. Zool. vol. xliv. 1886, p. 1.

The Microscope (Detroit), 1887-88.

Zeitschr. wiss. Zool. xlix. 1890, p. 209.

Ann. Sci. Nat. ser. 3, vol. xv. 1851, p. 158.

Zeitschr. wiss. Zool. vol. xlv. 1887, pp. 401-467, t. xx-xxii.

The breadth of the latter is estimated from Reinhard's figure.

The Echiuroid Gephyrea (see p. 434) are by some authorities considered to be a division of the Chaetopoda.

Another worm, Histriobdella (Histriodrilus) homari, which is parasitic on the eggs of the lobster, and which occurs on our coast, has been placed amongst the Archiannelida. It is a minute form, with peculiarities in its anatomy which render its affinities uncertain.

Quart. J. Micr. Sci. xxvii. 1887, p. 109.

J. Mar. Biol. Assoc. vol. i. (n.s.) 1889-90, p. 119.

Schimkewitsch, Zeitschr. f. wiss. Zool. lix. 1895, p. 46.

Hatschek, Arb. Zool. Inst. Wien, iii. 1881, p. 79.

Fraipont, "Le Genre Polygordius," Fauna u. Flora des Golfes v. Neapel, Monogr. xiv. 1887.

T. J. Parker, Lessons in Elementary Biology, London, 1891, p. 267, gives a full account of the anatomy and development of Polygordius.

"Die Capitelliden," Fauna u. Flora d. Golfes v. Neapel, Monogr. xvi. 1887, p. 350.

Encyclopaedia Britannica, 9th ed., Art. "Mollusca," p. 652.

Benham, "The Post-Larval Stage of Arenicola," J. Mar. Biol. Assoc. iii. (n.s.) 1893, p. 48.

The blood is colourless in Syllidae and Nephthydidae.

Ehlers states that some Eunicidae have green blood.

Benham, Quart. J. Micr. Sci. xxxix. 1896, p. 1.

Schaeppi, Jena. Zeit. xxviii. 1894, p. 217.

Goodrich, Quart. J. Micr. Sci. xxxiv. 1893, p. 387.

Benham, Quart. J. Micr. Sci. xxxii. 1891, p. 325. See also Bourne (nephridium of Polynoë), Tr. Linn. Soc. (Zool.), ii. 1883, p. 357; Meyer, for nephridium of Terebellidae, Sabellidae, and Cirratulidae, in Mt. Zool. Stat. Neapel, vii. 1887, p. 592.

It is worthy of note that in Aeolosoma alone amongst the Oligochaeta does the brain lie in the prostomium in the adult.

Andrews, "The Eyes of Polychaetes," J. Morph. vii. 1892, p. 169.

Wistinghausen, "Entwick. v. N. dumerilii," Mt. Zool. Stat. Neapel, x. 1891, p. 41.

This is a modification of the classification proposed by me at the meeting of the British Association at Oxford, 1894 (see Report, p. 696). For further characteristics of these Orders and sub-Orders see below Chap. XII. Ehlers, "Die Borstenwürmer," 1864, gives a historical survey of the group, and enumerates the earlier classifications.

In Coabangia (see p. 284) the anus is near the anterior end, on the ventral surface.

It is doubtful whether these organs are palps or only lateral lips.

Pruvot traced the nerve supply to these organs, and thus established their homology. Arch. d. Zool. Expér. (ser. 2) iii. 1885, p. 211.

Meyer, "Stud. ub. d. Körperbau der Anneliden," Mt. Zool. Stat. Neapel, vii. 1887, p. 592; viii. 1888, p. 462. In this work a great number of important and interesting anatomical facts are recorded with respect to the Terebelliformia and Sabelliformia, as well as certain details as to the structure and development of the nephridia.

In some of the members of this family paired lateral tentacles appear to exist.

It is possible that some of these may be peristomial.

Individual cases in which chaetae are present have been recorded.

Meyer, loc. cit.

Haswell, P. Linn. Soc. N.S. Wales, vii. 1883, p. 251.

Eisig, "Die Capitelliden," Fauna u. Flora G. v. Neapel, Monogr. xvi. 1887, p. 331.

Compare with this the muscular organ of Dinophilus, p. 243, Protodrilus, and a similar structure which occurs in Terebellids.

Korschelt, "Über Ophryotrocha puerilis," Zeitschr. f. wiss. Zool. lv. 1893, p. 224.

Eisig, Mt. Zool. Stat. Neapel, ii. 1881, p. 255.

They are specially large also in the Typhloscolecidae; while Racovitza (Ann. Mag. N. H. (ser. 6), xv. 1895, p. 279) has recently suggested that the caruncle of Amphinomidae belongs to the category of nuchal organs, and compares it with the ciliated lappets of Pterosyllis.

Ehlers, Zeitschr. f. wiss. Zool. liii. 1892, p. 217.

See Claparède and Metschnikoff, "Beit. zur Kennt. d. Entwick der Chaetopoden," Zeitschr. f. wiss. Zool. xix. 1869, p. 163; and Fewkes, "On the Development of certain Worm Larvae," Bulletin Mus. Harvard, xi. 1883, p. 167.

For an account of the anatomy and development of a Trochosphere, see Hatschek, on Eupomatus, in Arbeit. Zool. Inst. Wien, vi. 1885. Also Meyer, Mt. Zool. Stat. Neapel, viii. 1888, p. 462; and for Polynoid larva see Häcker, Zool. Jahrb. Abth. Anat. viii. 1895, p. 245.

See Meyer (ref. on p. 261).

Many of the Polynoids are sexually dimorphic.

Claparède, "Annélides Chétopodes du Golfe de Naples," Supplement, 1870; and Wistinghausen, Mt. Zool. Stat. Neapel, x. 1891, p. 41.

Claparède used the term "epigamous" for this phase; Ehlers employed the term "epitokous," whilst he called the "Nereid" phase "atokous," under the impression that the worm did not become mature in this condition.

Malaquin gives a detailed account of the asexual reproduction in Syllidae in Recherches sur les Syllidiens, Lille, 1893, and in Revue Biol. d. Nord de la France, iii. 1891. See also St. Joseph, "Les annelides polychétes des côtes de Dinard," Ann. Sci. Nat. Zool. (7th ser.) i. 1886, p. 134.

Alex. Agassiz, Boston J. Nat. Hist. vii. 1863, p. 384.

Huxley, Edinb. New Philosoph. Journ. 1855, i. p. 113.

"Challenger" Reports, vol. xii. 1885, "Polychaeta," p. 198; and Oka, Zoolog. Centralbl. ii. 1895, p. 591.

Two new heads have been observed in Typosyllis variegata by Langerhans, and two new tails in another Syllis.

Dalyell, The Powers of the Creator revealed, etc., vol. ii. 1853, p. 225 et seq.

von Kennel, Arb. Zool. Instit. Würzburg, vi. 1883, p. 259.

Leidy, Proc. Acad. Nat. Hist. Philadelphia, 1883, p. 204.

Giard, C. R. Soc. Biol. v. 1893, p. 473.

See M‘Intosh, Ann. Mag. Nat. Hist. (ser. 4) ii. 1868, p. 276.

Lankester has suggested that a strong acid is secreted for the purpose, see Ann. Mag. Nat. Hist. (ser. 4) i. 1868, p. 233.

M‘Intosh, Ann. Mag. Nat. Hist. (ser. 6) xiii. 1894, p. 1.

Dalyell, The Powers of the Creator revealed, ii. 1853, p. 217.

Watson, Journ. R. Mic. Soc. 1890, p. 685; see also Dalyell, loc. cit. ii. p. 195.

Schmiedeberg, Mt. Zool. Stat. Neapel, iii. 1882, p. 373.

For pelagic forms, see Camille Viguier, Arch. de Zool. Expér. (ser. 2) iv. 1886, p. 347; also Reibisch, Die pelag. Phyllodociden u. Typhloscoleciden d. Plankton Exped. 1895.

Lankester, Journ. Anat. and Physiol. 1868, p. 114; and 1870, p. 119; see also MacMunn, "On the Chromatology of the Blood in some Invertebrates," Quart. J. Micr. Sci. xxv. 1885, p. 469.

For coloured pictures of worms consult Schmarda, "Neue wirbellose Thiere," 2nd part, 1861; Milne Edwards in Cuvier's "Règne Animal" (Ed. Disciples de Cuvier).

Semper, Animal Life, "Internat. Sci. Series," 1881, p. 401.

The experiments were made by Mr. Garstang at the Laboratory of the Marine Biological Association, and are recorded by Poulton in The Colours of Animals, "Internat. Sci. Series," 1890, p. 201.

Panceri, Atti Acad. Sci. Napoli, vii. 1875.

M‘Intosh, H.M.S. "Challenger" Reports, "Polychaeta," vol. xii. p. ix.

For an account of these worms see M‘Intosh, loc. cit. p. 257.

For a list of parasitic Polychaetes see St. Joseph, Ann. Sci. Nat. (ser. 7) v. 1888, p. 141.

Semper, loc. cit. p. 340.

See "Challenger Reports," and St. Joseph, loc. cit.

"Challenger" Reports, loc. cit. p. xxx.

See Hornell, Fauna of Liverpool Bay, Report III. 1892, p. 126.

Zittel, Handbuch d. Palaeontologic (Palaeozoologie), i. 1876-80, p. 562.

Ehlers, Zeitschr. f. wiss. Zool. xviii. 1868, p. 241.

The Chaetopteridae may have to be placed elsewhere in the system, as they are peculiarly modified, and present features recalling the Cryptocephala, from which it is possible they have descended.

Meyer (Mt. Zool. Stat. Neapel, vii. 1887, p. 669, note) suggests that the tentacular filaments of Cirratulids are really prostomial, but have shifted back on to the peristomium, or even farther.

It is probable that the genital ducts of Sternaspis and Chlorhaemids are modified nephridia.

The character of head and parapodium in each family will be gathered from the figures accompanying the general description in Chap. X., so that detailed description is unnecessary. In all cases the chaetae form valuable specific characters.

The examples of the various families are British, unless the opposite is expressly stated; but most of them are not confined to our shores, and the foreign localities are usually given. No attempt is made to enumerate all the British species.

The following books may be found useful for identifying the worms:—

Malaquin, Recherches sur les Syllidiens, 1893; for structure of the gizzard, see also Haswell, Quart. J. Micr. Sci. xxvi. 1886, p. 471; and xxx. 1889, p. 31.

See M‘Intosh's Memoirs, loc. cit.

Herein are included the various genera formed by Kinberg, Malmgren, and others.

It appears to be the same as P. grubiana Clap.

Marenzeller has shown that Johnston's P. scolopendrina is not identical with that of Savigny, and suggests the above name for it.

F. Buchanan, "Report on Polychaetes, Part I." Sci. Proc. Roy. Dublin Soc. vii. (n.s.) 1893, p. 169.

Polyodontes Ran. deserves mention as being a large, rare form with peculiar pedal gland; cf. Eisig (ref. on p. 268), p. 324; and Buchanan, Quart. J. Micr. Sc. xxxv. 1894, p. 433.

Many authorities regard this species as synonymous with Savigny's P. laminosa.

According to a verbal communication from Mr. J. Hornell of Jersey, they belong to P. maculata Müll., while Mr. Garstang believes them to belong to Eulalia viridis.

These segmentally-arranged brown spots may perhaps be photogenic.

Greef, Acta Ac. German., xxxix. 1877.

Greef, Zeitschr. f. wiss. Zool. xlii. 1885, p. 432.

Buchanan, Quart. J. Micr. Sci. xxxv. 1894, p. 445.

Buchanan, Sci. Proc. R. Dublin Soc. viii. (n.s.) 1893, p. 169.

Reibisch, Phyllodociden u. Typhloscoleciden d. Plankton Exped. 1895.

The British species is usually referred to as C. insignis Baird, but Joyeux Laffuie (Arch. Zool. Exp. (ser. 2) viii. 1890, p. 244) has shown that there is only one European species. It is possible that there is a closer affinity with the Sabelliformia than is at present supposed.

Compare Sternaspis, p. 336.

For literature, see Benham, Quart. J. Micr. Sci. xxxix. part 1, 1896, p. 1.

F. Buchanan, Quart. J. Micr. Sci. xxxi. 1890, p. 175.

In some genera there are no gills, e.g. Leaena.

These characters are not necessarily generic.

Eisig, "Die Capitelliden," Fauna u. Flora G. v. Neapel, Monogr. xvi. 1887.

Ed. Meyer., Arch. mikr. Anat. xxi. 1882, p. 769.

Vejdovsky, Denk. Akad. Wien, xliii. 1882, part 2, p. 33; and Rietsch, Ann. Sci. Nat. (Zool.) ser. 6, xiii. 1882, art. 5.

For anatomy see Meyer, Mt. Zool. Stat. Neapel, vii. 1887.

Andrews, Journ. Morph. v. 1891, p. 271.

A. G. Bourne, Quart. J. Micr. Sci. xxiii. 1883, p. 168.

Closely allied is Manayunkia Leidy, which occurs in fresh-water lakes of America. Another fresh-water genus is Coabangia Giard, which perhaps deserves the creation of a special family. The anus is ventral and anterior. The chaetae are peculiarly arranged, dorsal uncini being present only on four segments. The first body segment carries a ventral bundle of five great "palmate" chaetae.

For the anatomy see Meyer, Mt. Stat. Neapel, vii. 1887; see also above, p. 306.

von Graff, "Myzostomida," "Challenger" Reports, part 27, vol. x. 1884; and "Supplement," part 61, vol. xx. 1887.

Marenzeller, Anz. Akad. Wien, xxxii. p. 192.

Mt. Zool. Stat. Neapel, xii. 1896, p. 227; where, too, see literature.

Beard, Mt. Zool. St. Neap. v. 1884, p. 544.

Quart. J. Micr. Sci. (n.s.) vol. iv. 1864, p. 258; and v. pp. 7, 99.

Zeitschr. wiss. Zool. xix. 1869, p. 563.

De Lumbrici terrestris Historia naturali, Brussels, 1829.

Naturg. ein. Wurm-Arten d. süssen u. salzigen Wasser, Copenhagen, 1771.

Trans. Roy. Soc. Victoria, vol. i. 1888, p. 1.

Phil. Trans. clxxxvi. 1895, A, p. 383.

Mém. cour. Ac. Belg. lii. 1890-93.

Quart. J. Micr. Sci. xxxi. 1890, p. 83.

Beddard, Ibid. xxxiii. 1892, p. 325.

Beddard, Ann. Mag. Nat. Hist. (6) xiii. 1894, p. 205.

Mém. Soc. Zool. France, iii. 1890, p. 223.

Vegetable Mould and Earthworms, London, 1881.

Zool. Anz. xi. 1888, p. 72.

See Fletcher, P. Linn. Soc. N.S.W. (2) iii. 1889, p. 1542.

In Sitzungs-Ber. Böhm. Ges. 1889, p. 183.

See Dr. Rosa in Ann. Hofmus. Wien, vi. 1891, p. 379.

Entwickelungsgeschichtliche Untersuchungen, Prag, Heft i. 1888, p. 33.

See Kleinenberg, Quart. J. Micr. Sci. xix., 1879, p. 206.