The Project Gutenberg eBook of The British Woodlice, by Wilfred Mark Webb, F.L.S.

The members of this genus are very much like those of Trichoniscus. In the latter, however, the hinder legs are longer in proportion and the eyes are compound.

1879 Trichoniscus albidus Budde-Lund (7) p. 9.
1898 Trichoniscoides albidus Sars (59), p. 165, pl. LXXIII., fig. 2.

We are able to include this species, as a specimen was found by Mr. Webb at Eton Wick in the summer of 1899. It is one of a number of species which the Rev. Canon Norman (49, p. 18) suggested as likely to be British. It is the only representative of its genus, which does not differ in any very important characters from the others in the family. The narrow elongated body will serve to separate it from Trichoniscus vividus and Trichoniscus roseus, but on account of its size, which is much the same as that of Trichoniscus pusillus and the two British species of Haplophthalmus, it will be advisable to give some further points of distinction. From the first its white colour will serve to differentiate it; the other two lack the narrow abdomen seen in Trichoniscoides albidus. Moreover, not one of the three shows the serrations on the side plates which characterise the species under consideration. Platyarthrus hoffmannseggii is small and white and the edges of its side plates are toothed, but it is oval in shape, possesses no eyes, and its stout antennæ have but a single joint to the flagellum instead of four. On the Continent this species has been found in rich soil.

Abdomen broad (comparatively); eyes simple; flagellum with three joints; back with longitudinal ridges.

The body of Haplophthalmus is long in proportion to its width, but there is no abrupt decrease in the breadth of the abdomen as seen in Trichoniscus and Trichoniscoides. The eyes are simple as in the latter genus and the lateral lobes of the head are rather large, while the side plates of the body are well separated.

1844 Itea mengii Zaddach (77), p. 16.
1860 Haplophthalmus elegans Schöbl (66), p. 449.
1885 Haplophthalmus mengii Budde-Lund (8), p. 250.
1898 Haplophthalmus mengii Sars (59), p. 167, pl. LXXIV., fig. 1.

The Rev. Canon Norman discovered two specimens of this species in Ireland in June, 1900 (50); in the previous year one of us (Mr. Webb) found a single example at Eton Wick.

The main differences between the members of this genus and their allies are set forth in the generic description and incidentally elsewhere, so we shall content ourselves with giving the distinctive points of the two British species. Haplophthalmus mengii has a number of raised longitudinal ribs on each segment of the thorax, the outer ridges being somewhat broken. There are also two prominent ribs upon the third segment of the abdomen.

1870 Haplophthalmus elegans Budde-Lund (6), p. 228 (not Haplophthalmus elegans Schöbl).
1879 Haplophthalmus danicus Budde-Lund (7), p. 9.
1881 Haplophthalmus mengii Weber (76), p. 192, pl. V., figs. 7-9 (not Itea mengii Zaddach).
1885 Haplophthalmus danicus Budde-Lund (8), p. 250.
1898 Haplophthalmus danicus Sars (59), p. 168, pl. LXXIV., fig. 2.

This species was added to the British list by the Rev. Canon Norman (49), who found a colony in his garden at Berkhamsted. It has rows of tubercles on its thorax instead of ridges, and there are no ribs at all upon the abdomen. The front of the head projects further comparatively and forms a more acute point than in Haplophthalmus mengii and it is not so purely white in colour as the latter species.

England: Warley Place; (W.M.W. from Miss Willmott): Queen's Cottage, Kew Gardens; Stanmore; Hanwell, garden at Odstock, Bennett's Nurseries; (W.M.W.): Berkhamsted; (Norman, 49): Sunderland; (Brady, 50a).

Europe: France; (25): Denmark; Holland; Germany; (Dollfus, Feu de Jeun, Nat., April, 1896): Norway; (Sars, 59).

Section—ONISCI.

THE OUTER DIVISIONS OF THE TAIL APPENDAGES BROADER THAN THE INNER ONES.

Family—ONISCIDÆ.

Tail appendages projecting when the animal is walking.

(1.) Unable to roll up into a complete ball.

Genus—ONISCUS Linné 1746 (41), p. 360.

The characters given above taken in conjunction with the size of the animals will serve to distinguish the members of this genus.

1761 Oniscus asellus Linné (41), p. 500, No. 2058.
1792 Oniscus murarius Cuvier (9), p. 22, pl. XXVI.
1838 Oniscus fossor Koch (34), part 22, pl. XXII.
1868 Oniscus asellus Bate and Westwood (1), p. 468.
1868 Oniscus fossor Bate and Westwood (1), pp. 471-2.
1898 Oniscus asellus Sars (59), p. 171, pl. LXXV.

Oniscus asellus is one of the largest of our woodlice and it is also probably the commonest, though Porcellio scaber is in many places quite as abundant. The body of Oniscus is broad and expanded and the colour is usually a slate grey with yellowish markings more or less regularly arranged.

From the genus Porcellio the species with which we are concerned is at once distinguished by the three jointed flagellum. Porcellio has but two joints and has, besides, a prominent lobe projecting from the middle of the head, which is not seen in Oniscus. Philoscia, although it has three joints to the flagellum, has a narrow abdomen and lacks entirely the lateral lobes which are a feature of the other genera of Oniscidæ.

Oniscus fossor of Koch (34) was recognized by Kinahan and by Bate and Westwood as a species. Dr. Scharff submitted specimens to Professor Budde-Lund who found no differences between them and Oniscus asellus. The former (63) mentions, however, that the characteristics of the supposed species are those of young examples of Oniscus asellus, and Professor Sars (59, p. 173) seems to be of the same opinion. Many young examples of Oniscus asellus that we have examined have a curious whitish transverse band owing to the light colour of the dorsal plates of the first abdominal segments. The flagellum also does not seem to shew in young animals a distinct division into three joints.

England: High Beach, Epping, including an albino; Maldon; Brightlingsea; Iver; Hanwell; Eton; Kew; Pamber Forest; Kingston-on-Soar; Bluebell Hill, Maidstone; (W.M.W.): Lynmouth; (W.M.W. from J.T.C.).

Scotland: (Scharff, 63). Dinnet, Aberdeenshire; (W.M.W. from Madame Christen).

Europe: Almost throughout; (12): France; (25): Spain; (12): Sweden Norway; Denmark; Germany; Holland; Italy; Iceland; (59): Faroe Islands; Thorsharn; (R.F.S.)

If any further differences of an obvious kind be required to distinguish Philoscia from Oniscus, one at least will be found in the much greater development of the hinder legs in the former genus.

1763 Oniscus muscorum Scopoli (67), p. 415.
1793 Oniscus sylvestris Fabricius (26), p. 397.
1793 Oniscus agilis Koch in Panzer (51), part 9, pl. XXIV.
1833 Philoscia marmorata Brandt (3), p. 183.
1838 Ligia melanocephala Koch (34), part 22, pl. XVIII.
1847 Zia melanocephala Koch (38), part 40, pl. I. p. 212.
1868 Philoscia muscorum Bate and Westwood (1), p. 450.
1898 Philoscia muscorum Sars (59), p. 174, pl. LXXVI., fig. 1.

This species lives chiefly at the roots of grass and under the stones or sticks that lie among it. Philoscia muscorum has a very smooth and shining body, and its long legs enable it to move very rapidly. The ground colour of its dorsal surface varies from light yellow to deep brown. There are characteristic dark markings down the middle of the thorax and on the sides, between which are lighter patches. In dark coloured specimens the markings are by no means so evident.

England: High Beach, Epping; Warley; (W.M.W.): Maldon; (W.M.W. from R.M.): Kew; Langley; Hanwell, yellow variation; Bluebell Hill, Maidstone; (W.M.W.): Liphook; (C.S.): Pamber Forest; Kingston-on-Soar; (W.M.W.)

Europe: France; (25): Spain; (12): Sicily; (19): Hertsogovinia; (22): Sweden; (21): Norway; Denmark; Prussia; Germany; Holland; Poland; Austria; Italy; (59): Sardinia; (21).

1858 Philoscia couchii Kinahan (33), p. 195, pl. XXIII., fig. 4.
1868 Philoscia couchii Bate and Westwood (1), p.
1885 Ligidium couchii Budde-Lund (8), p. 257.
1885 Philoscia longicornis Budde-Lund (8), p. 221.
1897 Philoscia couchii Dollfus (21), p. 72, pl. I., fig. 1.

Philoscia couchii is an inhabitant of the sea-side; it is smaller than the last species, its colour to the naked eye is a uniform lead-grey, and its antennæ are very large (compared with its size) and hairy.

This species was discovered by Professor Kinahan when in the company of Messrs. Bate and Westwood near Polperro in Cornwall in the year 1858, and dried specimens presented by him are in the British Museum (Natural History).

England: Talland Cove; Polperro; (Bate and Westwood, 1): Salcombe, Devon; (Norman, 49): Meadefoot, Torquay; (Stebbing in 49).

The broad body, which is much flattened, and the very thick antennæ distinguish Platyarthrus from the other small woodlice (Trichoniscidæ).

1833 Platyarthrus hoffmannseggii Brandt (3), p. 174, pl. IV., fig. 10.
1844 Itea crassicornis Koch (34), part 36, pl. V.
1860 Typhloniscus steinii Schöbl (66), p. 282.
1868 Platyarthrus hoffmannseggii Bate and Westwood (1), p. 464.
1898 Platyarthrus hoffmannseggii Sars (59), p. 175, pl. LXXVI., fig. 2.

Up to the present this is the only woodlouse which has been found in the nests of British ants. It is small and oval, its colour is white, and its body is covered with tubercles. The edges of its side plates are toothed, its flagellum has but a single joint and it has no eyes.

Miss Kate Hall tells us that, if very hungry, ants in captivity will kill and eat Platyarthrus. With regard to its own food, Lord Avebury has favoured us with the opinion that it lives on the spores of the lower plants, such as would be found in the ants' nest.

England: Warley; Hanwell; West Drayton; Langley; Kingston-on-Soar; Bluebell Hill, Maidstone; (W.M.W.): Berkhamsted; Salcombe; Devon; Cheddar Cliffs, Somerset; (Norman, 49): Ide, near Exeter; (Parfitt, 53): Torquay; (Stebbing in 49); Lulworth Cove; (Rev. A. R. Hogan teste Bate and Westwood, 1): Hammersmith; Oxford; Berry Head, Torquay; Plymouth; (Bate and Westwood, 1): In the nest of Myrmica rubra, Newton Ferrers (E. E. Lowe).

Ireland: Leixlip, Co. Dublin; Lismore, Co. Waterford; Glengariff, Co. Cork; (Scharff, 63): Bagenalstown, Co. Carlow; (64).

Europe: France; (28): Spain; (12): Denmark; Germany; Holland; Bohemia; Austria; Tyrol; Helvetia; (59).

NOTE.—In the genera which follow, air-tubes or air-cavities (tracheæ) are present in the outer plates of the abdominal appendages, 1 and 2, or 1 to 5. The appendages in question have in consequence a milk-white appearance in the living animal owing to the fact that the enclosed air reflects white light. Considerable interest attaches to the study of these tracheæ, which have the same function as those of insects, but which have been independently developed. To emphasise the latter fact the structures are often termed "pseudotracheæ."

Porcellio is easily separated from the previous genera—Oniscus, Philoscia, and Platyarthrus—by its two-jointed flagellum. The fact that the abdomen is not abruptly narrowed separates it from Metoponorthus, which also lacks the prominent frontal lobe so characteristic of Porcellio. The species of this genera might be confused with Cyclisticus which has two joints to the flagellum and a broad abdomen, but the latter genus has the power of rolling itself into a ball, while its frontal lobe is very small, and the first segment of its thorax is comparatively larger than in any species of Porcellio.

1804 Porcellio scaber Latreille (37), p. 45.
1818 Oniscus granulatus Lamark (36), p. 261.
1818 Porcellio nigra Say (62), p. 432.
1840 Porcellio brandtii Milne-Edwards (46), p. 168.
1840 Porcellio dubius Koch (34), part 34, pl. VIII.
1847 Porcellio asper Koch (35), p. 207, pl. VIII., fig. 98.
1857 Porcellio montezumæ Saussure (60), p. 207.
1865 Porcellio paulensis Heller (31), p. 136, p. XII., fig. 5.
1868 Porcellio scaber Bate and Westwood (1), p. 475.
1876 Porcellio graniger Miers (44), p. 223.
1885 Porcellio graniger Budde-Lund (8), p. 149.
1898 Porcellio scaber Sars (59), p. 176, pl. LXXVII.

The body of Porcellio scaber is densely covered with tubercles. Its colour is usually of a very dark grey, but at times it is quite red or variegated with yellow. Albino specimens have been recorded. The two joints of the flagellum are of the same length and together equal that of the last joint of the peduncle. Air-tubes are present in the outer plates of the first two abdominal appendages.

England: High Beach, Epping; Warley; Brightlingsea; (W.M.W.): Maldon; (W.M.W. from R.M.): Langley; Kew; Skirmett; Pamber Forest; (W.M.W.): Liphook; (C.S.): Stoke-on-Trent; Kingston-on-Soar; (W.M.W.)

Europe: Throughout; (59): France; (28): Spain; (15): Iceland; (59): Faroe Isles—Thorsharn and Naalsoe—(R.F.S. and B.M., N. Annadale).

America: Greenland; North America; Sandwich Isles; (B.M.); Mexico; (59): St. Paul; St. Croix; (59); Ascension; Tristan d'Acunha; (23)

1833 Porcellio pictus Brandt and Razteburg (4), p. 78, pl. 12, fig. 5.
1839 Porcellio melanocephalus Koch (34), part 28, pl. XVIII.
1853 Porcellio melanocephalus Schnitzler (65), p. 24.
1856 Porcellio mixtus Fitch (29), p. 120.
1868 Porcellio pictus Bate and Westwood (1), p.
1898 Porcellio pictus Sars (59), p. 177. pl. LXXVII., fig. 1.

There are tubercles on the body of Porcellio pictus, which is a striking looking animal. Its head is black with the lateral lobes curved outwards; there is a dark band down the middle of the back and commonly two others on each side, with more or less conspicuous yellow markings between.

The distal (terminal) joint of the flagellum is but half the length of the proximal one and the last peduncular joint is longer than the two combined.

England: Maldon; (W.M.W. from R.M.): Chislehurst; (Bate and Westwood, 1): Cooper's Hill, near Cheltenham; (Norman, 49): Exeter; (Parfitt, 53): Kent; (Bate and Westwood, 1.)

Scotland: Between Leith and Portobello; (Scott, 68): Cumbrae (Scott, 68a): Ayrshire; (Boyd in Norman, 49): Banff; (T. Edwards in Norman, 49).

Ireland: Dublin; Belfast; (Bate and Westwood, 1): Galway; Maryborough; Queen's Co., Castel; and Caher Co. Tipperary; (R.F.S.)

Europe: France; (25): North, West-Central, and East Europe; (8): Sweden; Norway; Denmark; Germany; Hungary; Russia; (59).

1833 Porcellio dilatatus Brandt and Ratzeburg (4), p. 78, pl. 12., fig. 6.
1840 Porcellio scaber Milne-Edwards (not Latreille) (46), p. 167.
1868 Porcellio dilatatus Bate and Westwood (1), p.
1898 Porcellio dilatatus Sars (59), p. 179, pl. LXXVII., fig. 2.

The fact that Porcellio dilatatus is more than half as broad as it is long, at once distinguishes it from the other species of Porcellio. It is tuberculated and of somewhat a lighter grey than Porcellio scaber usually is. The two species agree in having the two joints of the flagellum equal, but the last peduncular joint, as in Porcellio pictus, is longer than the flagellum.

As in the two preceding species, air-tubes are found in the outer plates of the appendages on the first two abdominal segments. Porcellio dilatatus is to be looked for near houses.

England: Maldon; (W.M.W. from R.M.): Eton; (Stebbing from W.M.W., 71a): Berkhamsted; (Norman, 50): Headley, Surrey; Ventnor; (Stebbing in Norman, 49).

Ireland: Dublin; (Scharff, 63): Dundrum; (Scharff in Norman, 50): Galway; Roundstone; (R.F.S.): Belfast; (C. W. Buckle, Irish Nat., Vol. XI. (1902), p. 43).

Europe: France; (25): Spain; (12 ): Denmark; Norway; Germany; Poland; Holland; (59).

1833 Porcellio rathkei Brandt (3), p. 177, fig. 10.
1833 Porcellio ferrugineus Brandt (3), p. 178.
1840 Porcellio trilineatus Koch (34), part 34, pl. IX.
1853 Porcellio trivittatus Lereboullet (39), p. 54, pl. I., figs. 13 and 14.
1853 Porcellio tetramoerus Schnitzler (65), p. 24.
1853 Porcellio striatus Schnitzler (65), p. 24.

There is often a light band down the back and one on either side of it near the margin in Porcellio rathkei (especially in the males), with other more irregularly arranged light patches between. Unlike the three species previously considered, the present one has a smooth body. The distal joint of the flagellum is the longer, and the flagellum itself is equal in length to the last joint of the peduncle.

Some specimens found by Mr. Webb in 1899 at Eton were submitted to Mr. Stebbing, and since then the former has found Porcellio rathkei to be pretty generally distributed in West Middlesex, where the species appears to frequent the open fields.

Air-tubes occur in abdominal appendages 1 to 5 and the white appearance of all of these at once serves to distinguish the living animal from Porcellio scaber in which the first two pairs of abdominal appendages alone are white.

England: Eton; (Stebbing, 71a): Lane End; (Stebbing, from the Misses Johnston, 71a): Acton; Ealing; Hanwell; Southall; Northolt; Greenford; West Drayton; Mortlake; (W.M.W.); Sunderland; (Brady, 50a).

Europe: France; (25): Bosnia; Servia; (22): Hertzogovania (B.M.); Norway; Northern, Western, and Middle Europe, everywhere; (59): Corfu (B.M.)

1804 Porcellio laevis Latreille (37), p. 46.
1827 Porcellio degeerii Savigny and Audouin (61), p. 289.
1833 Porcellio cucercus Brandt (3), p. 177.
1833 Porcellio syriacus Brandt (3), p. 178.
1833 Porcellio musculus Brandt (3), p. 180.
1833 Porcellio cinerascens Brandt (3), p. 178.
1833 Porcellio dubius Brandt (3), p. 178.
1837 Porcellio poeyi Guérin (30), p. 6.
1844 Porcellio urbicus Koch (34), part 36, pl. IV.
1847 Porcellio flavipes Koch (35), p. 206, pl. VIII., fig. 97.
1853 Cylisticus laevis Schnitzler (65), p. 25.
1857 Porcellio cubensis Saussure (60), p. 307.
1857 Porcellio sumichtasli Saussure (60), p. 307.
1857 Porcellio cotillæ Saussure (60), p. 307.
1857 Porcellio aztecus Saussure (60), p. 307.
1857 Porcellio mexicanus Saussure (60), p. 307.

Another smooth species is Porcellio laevis. The colour of its body is light grey with irregular white markings. The large size of this species and the very long tail-appendages of the males are features which will help to identify it. The distal joint of the flagellum is slightly the longer and as in the last species (P. rathkei) the flagellum is equal in length to the last joint of the peduncle. The chief habitats for this species are among vegetable rubbish near human dwellings.

England: Maldon; (W.M.W. from R.M.): Ipswich (1892); Hanwell; Wimbledon; (W.M.W.): Kent; (Kinahan, 32).

Ireland: Dublin; (Bate and Westwood, 1): Blackrock Dundrum; Co. Dublin; Galway; (R.F.S.)

Europe: France; (25): Spain; (15): Sicily; (19): Hertzogovania; (22): Sweden; Denmark; Germany; Belgium; Austria; Italy; Dalmatia; Greece; Turkey; (59); Corfu; (B.M.): Inca, Majorca (23); (B.M.—Pocock and Thomas.)

America: North America; Mexico; Peru; Brazil; Chili; West Indies; Pacific Islands; (59); Sandwich Isles; (B.M.)

1833 Porcellio ratzeburgii Brandt, (3), p. 178.
1839 Porcellio nemorensis Koch (34), part 28, pl. XIX.
1839 Porcellio lugubris Koch (34), part 28, pl. XX.
1853 Porcellio quercum Schnitzler (65), p. 24.
1898 Porcellio ratzeburgii Sars (59), p. 182, pl. LXXX, fig. 1.

There are granulations on the middle of the segments in Porcellio ratzeburgii and the sides of its body are more nearly parallel than in the other species of Porcellio; the frontal lobe is, practically speaking, semicircular and the lateral plates of the thorax flank the head to a considerable extent. As in Porcellio pictus, the dark band is in the middle of the back. The distal joint of the flagellum is nearly twice as long as the proximal, and the flagellum is shorter than the last joint of the peduncle. This species was added to the British list by Mr. Webb (74) in 1898.

Porcellio ratzeburgii agrees with Porcellio rathkei in having air-tubes in the first five abdominal appendages.

England: Warley; Brightlingsea; young examples (W.M.W.): Maldon; young examples (W.M.W. from R.M.)

Europe: Trafoi St. Martini, and Capitello, in the Tyrol; (Norman, 50); East Alps, very common; Val-de-Joux; Massif de la Chartreuse Vaulnaveys (25): Bosnia; (22): Norway; Central Europe; Upper Pfaltz; Bohemia; Saxony; Rhaetia; (59).

Genus—METOPONORTHUS Budde-Lund, 1879 (7), p. 4.
Porcellionides Miers, 1876 (44), p. 98.

The hinder legs of Metoponorthus are proportionately longer than in any other Oniscidæ save Philoscia. Both genera have a narrow abdomen, but Philoscia has an extra joint to the flagellum, and shows no sign of lateral lobes to the head.

1833 Porcellio pruinosus Brandt (3), p. 181.
1840 Porcellio truncatus Milne-Edwards (46), p. 173.
1840 Porcellio maculicornis Koch (34), part 34, pl. XVI.
1853 Porcellio frontalis Lereboullet (39), p. 63, pl. I, fig. 17.
1868 Porcellio pruinosus Bate and Westwood (1), p. 487.
1877 Porcellio (Porcellioides) flavo-vittatus Miers (45), p. 669 pl., LXVIII., fig. 4.
1898 Metoponorthus pruinosus Sars (59), p. 184, pl. LXXX., fig. 2.

Undamaged specimens of Metoponorthus pruinosus are of a beautiful bluish-grey colour, owing to a "bloom" which is easily brushed off, revealing a dark reddish-brown tint beneath it. The antennæ are long and have white markings upon them.

England: Maldon; (W.M.W. from R.M.): Hanwell; Eton Wick; Kew; Ipswich; Stoke-on-Trent; (W.M.W.): Chiselhurst; Oxford; (Bate and Westwood): Berkhamsted; Burnmoor; Durham; (Norman, 49): Exeter; (Parfitt, 53); Torquay; (B.M.—T.R.R.S.)

Ireland: Dublin; (Kinahan, 32): Foyle District; Donegal; Galway; Clonbrock, Co. Galway; Mornington, Co. Meath; Santry; Gleeson Park; Dundrum, Co. Dublin; Bray; (R.F.S.)

Europe: Practically all the Countries of Europe are given in Dollfus' list; (23).

Asia: Japan; China; Syria; Ceylon; Sumatra; Celebes; Phillipines; Caucasus; Himalayas; (23): Christmas Island; (B.M.)

America: North and South, almost everywhere, to judge from M. Dollfus' list; (23).

1857 Porcellio cingendus Kinahan (32), p. 279, pl. XIX., figs. 1468-9.
1868 Porcellio cingendus Bate and Westwood (1), p. 489.
1885 Metoponorthus simplex Budde-Lund (8), p. 188.

The colour of Metoponorthus cingendus is steel blue with red or yellowish spots. It has a raised line across each thoracic segment and its abdomen is narrower than in Metoponorthus pruinosus.

Ireland: Dublin; (B.M. from Kinahan); Mountain Districts of Dublin, Wicklow, and Cork; Coast of Kerry; Arran Islands; Achill, Co. Mayo; Roundstone, Co. Galway; Mallow, Caef Island; Glandore; Brock Haven, Co. Cork; Killoughrim Forest, Co. Wexford; Kenmare, Co. Kerry; (R.F.S.).

(2.) Able to roll up into a ball.

Genus—CYLISTICUS Schnitzler, 1853 (65), p. 24.

The characters given immediately above are almost those of Porcellio with which Cylisticus might, perhaps, be confounded. The latter has the power, however, of rolling itself into a ball, and the first segment of the thorax is comparatively larger than in any species of Porcellio, indeed the side plates of the segment in question entirely flank the head. These features, as well as the straight sides of the body and the arched back, connect Cylisticus with Armadillidium, from which the former is, however, at once separated by its long pointed tail appendages.

1778 Oniscus convexus De Geer (10), p. 553, pl. XXXV., fig. 11.
1833 Porcellio spinifrons Brandt (3), p. 177.
1836 Porcellio laevis Koch (34), part 6, pl. I.
1853 Porcellio armadilloides Lereboullet (39), p. 65. pl. I., fig. 18.
1853 Cylisticus laevis Schnitzler (65), p. 25.
1868 Porcellio armadilloides Bate and Westwood (1), p. 485.
1898 Cylisticus convexus Sars (59), p. 186, pl. LXXXI.

There is but a single species of Cylisticus found in this country, so that it is not necessary for us to go into much further detail with regard to it. Cylisticus convexus has the two joints of the flagellum about equal, and they together in turn closely approximate in length to the last joint of the peduncle. Mr. Stebbing says, in a letter, that British examples do not appear to have the "white tail-piece" seen in Continental ones. It is not noticeable in the preserved specimens which we have seen from Berkhamsted and Leixlip, but it is very evident in the living ones found at Hanwell and Maidstone.

England: Maldon; (W.M.W. from R.M.): Hanwell; Bluebell Hill, Maidstone; Eton; (W.M.W.): Berkhamsted; Portland; (Norman, 49).

Scotland: Salisbury Crags; Edinburgh; Lanarkshire; Rothesay; (Scott, 68): Killwinning; (John Smith fide Robertson, 57): Highgate; (Bate and Westwood, 1).

Ireland: Leixlip, Co. Dublin; Tempo, Co. Fermanagh; Goresbridge, Co. Kilkenny; (R.F.S.)

Europe: France; (25): Sweden; Norway; Denmark; Germany; Bohemia; Holland; Belgium; Turkey; Caucasus; (59).

Family—ARMADILLIDIIDÆ.

Tail appendages not projecting when the animal is walking.

Genus—ARMADILLIDIUM Brandt, 1833 (3), p. 184.

Flagellum, with two joints; outer division of the tail appendages expanded and broader at the hinder end.

The members of the genus Armadillidium are more likely to be confounded, by the uninitiated, with the "Pill-millipedes" than with other Woodlice. Excepting Cylisticus (which has long pointed tail appendages) no other British forms have the power of rolling themselves up into a complete ball. The very arched body is characteristic of Armadillidium, and so is the groove into which the basal joints of the antennæ fit when the creatures curl up.