Sp. Anceus forficularius Risso, DESMAR., Crust. PI. 46, fig. 7 (not fig. 6),
GUERIN Iconogr., Crust. PI. 27, fig. 7; Anceus maxillaris LAM., Cancer
maxillaris MONTAGU, Linn. Trans, vn. 1804, Tab. vi. fig. 2, DESMAR.
Crust. PI. 46, fig. 6.
650 CLASS X.
Praniza LEACH. Head triangular, narrower than thorax. ]\lan-
dibles not exsert. Trunk in females consisting of only three
segments, the last three being confluent, and forming a single
oval scutum broader than the preceding segments.
Sp. Praniza coeridata, Oniscus marinus SLABBER, SLABBER Natuurk. Vcr/uxt.
Tab. IX. figs, i, 2 (copied in Encycl. me'ih., Ins. et Crust. PI. 329, figs. 24,
25), MONTAGU Trans. Linn. xi. Tab. iv. fig. 2, &c.
Compare on this genus J. 0. WESTWOOD, Ann. des Sc. natur. Tom. xxvii.
1832, pp. 316332, PI. 6.
Family XVIII. Oniscides. Two middle antennas very short,
of only one or two joints. Last segment of tail short, with the
appendages of the last pair of caudal feet concealed or styliform.
Comp. J. F. BRANDT Conspectus Monof/rapkice Crustaceorum Oniscodormn,
LATREILLII, Bulletin de la Soctite imp. des Natural, de Moscou, vi. 1833,
pp. 171 193, Tab. iv. figs. 6 21.
These Isopods may be named Land-Asselli, for although some of
them keep to the sea-shore, they do not live in water. The most
live under stones, bark of trees, in chinks of walls, &c. They gnaw
various substances. At night especially they seek their food, which
consists principally of vegetable matters.
A. Oniscinea. -Basal joint of the last pair of abdominal feet
short, not produced beyond the last segment of abdomen. Antennae
geniculate, with from six to nine joints (the five basal joints thicker,
the terminal seta with one or two, three or four joints).
Tylos LATE. External antennas moderate, with nine joints, the
four terminal joints forming a short seta. Last pair of abdominal
feet lamellose, concealed under abdomen. Body contractile into a
Sp. Tylos Latreittil AUDOUIN, Tylos armadillo LATR., Cloporte SAVIGNY,
Descr. de VEgypte, Crust. PI. 13, fig. i, GUKRIN Iconoyr., Crust. PI. 31,
fig. 4, EDWARDS, Cuv. R. Anim. ed. illustr., Crust. PI. 70, fig. 2.
The first four pairs of abdominal feet have a broad quadrangular append-
age, in which longitudinal cavities with blind branchings are found. They
open at the inferior margin by a row of small foramina, and take up air
for respiration. The animal lives on the coasts of Egypt and Algiers.
Armadillo LATR. External antennas with seven joints. Styli-
form appendages of last pair of feet short, not .prominent. Body
contractile into a ball.
Sp. Armadillo variegatus LATE., Armadillidium pustidatum EDWARDS,
VILLERS Entom. Linn. Tab. xi. fig. 16, DESMAREST Crust. PI. 49, figs.
6, 7, &c.
To this division belong the Millepcdce, more used in medicine formerly
than at present, Armadillo officinarum, BRANDT, u. RATZEBURG Mediz.
Zool. n. Tab. 43, figs. 8 10, CUVIER 7?. Aid. ed. ill., Crust. PI. 17,
fig. 4 ; from the south of Europe and Syria.
Sub-genera : Armadillidium BRANDT, Diploexochus ejusd., Cubaris
ejuscL, Armadillo ejusd.
Oniscus nob. (species from genus Oniscus L., Porcellio, Oniscus,
PJtiloscia LATE.). External antennae with from six to nine joints.
External appendage of last pair of abdominal feet styliform, exsert.
Deto GUERIN. External antennae with nine joints, the four ter-
minal joints small, forming a very short seta. Styliform appendages
at last segment of body elongate.
Sp. Deto echinata GUERIN, Magas. de Zool. 1836. Crust. PI. 14.
Note. In these genera the external antennae are six-jointed.
Oniscus LATH. External antennae with eight joints, inserted
under the anterior margin of head, which is somewhat prominent.
Body not contractile into a ball.
Sp. Oniscus asellus L., Oniscus murarius Cuv., DE GEER Mem. p. s. a V Hist,
des Ins. vn. PI. 35, fig. 3, GEOFFR. Ins. n. PI. xxn. fig. i, BRANDT, u.
RATZEBURG Medizin. Zool. u. Tab. xn. fig. 7 ; the cellar- oniscus, mostly
7'" or 8'" long, ash-grey above, with yellow spots on the side. This little
animal is very common on walls in moist places.
Porcellio LATR. External antennae with seven joints. Body in
most not contractile into a ball.
Sp. Porcellio scaber LATR., BRANDT u. EATZEBURG Mediz. Zool. n. Tab. xn.
fig. 6, GUERIN Iconogr., Crust. PI. 31, fig. 7. In Porcellio and Armadillo
(not in Oniscus} the external plates or covers of the two anterior abdominal
feet have a whitish body, which is hollow internally, and receives air from
a fissure by many openings. See DUVERNOY et LEREBOULLET Ann. des Sc.
nat. IQ Sdrie. Tom. xv. 1841. Zool. pp. 197, 198; comp. V. STEBOLD in
MUELLER'S Archiv, Jahresbericlit, p. 141. LEREBOULLET found a similar
structure in the external plate of the first five abdominal feet of two species
of Porcellio, which roll themselves up, whence he named one of these Pore,
armadilloldes. Already DE GEER had noticed such a species that rolls
itself up, Oniscus convexus, vii. p. 553, PI. 35, fig. n.
652 CLASS x.
Philosda LATR. External antennae with eight joints, naked at
the base. Segments of tail abruptly narrower behind the last
segment of trunk.
Sp. Oniscus muscorum Cuv.
B. Ligiea. Basal joint of last pair of abdominal feet slender,
elongate, exsert, terminated by two long styles. External antennae
terminated by a seta composed of several (twelve to twenty) joints,
Sp. Ligia oceanica FABR., BASTEE Natuurh Uitspann. 11. Tab. xiu. fig. 4,
DESMAR. Crust. PI. 49, figs. 3, 4 ; Ligia italica FABR., GUERIN Iconogr.,
Crust. PI. 31, fig. 5, &c. These animals live on the sea-coast, but often
leave the water and climb on atones, piles, &c. This genus forms the
transition to the water-onisci.
Some species, in their antennae resembling Ligia, have at the last
abdominal feet a bifid basal piece, and at the extremity of these two
pedicles is a filiform appendage. They live under stones or under
moss, in moist meadows, in decaying wood, &c. They form the
genus Ligidium BRANDT, Zia KOCH, in HERRICH-SCH^EFFER Deutschl.
Ins. Heft 180.
Sp. Ligidium Personii BRANDT, Oniscus ayilis PERSOON, PANZER Devischl.
Ins. Heft 9, Tab. 24, &c.
Family XIX. Asellota. Antennas four, distinct. Terminal
appendages of last pair of abdominal feet produced beyond the
body like a tail. Last segment of tail large, scutiform.
A. First pair of feet, either similar to the rest, or thickened at
the apex, and with hook single.
t Four antennas unequal, external much longer than internal.
* All the feet similar, terminated by short double claw.
Oniscoda LATR. (Janira LEACH).
Sp. Janira Nordmanni RATHKE, Fauna der Krym, p. 388, Tab. vi.
Sp. Jcera nivalis KROEYER, Gronland's Amfipoder, Tab. iv. fig. 21.
* Anterior feet short, thickened at the apex, furnished with hook in-
Munna KROEYER. External antennas very long. Feet, except
the first pair, longer than body. Tail destitute of appendages.
Sp. Munna Boeclcii KROEYER, Tidsskrift, n. 1839, PP- 612 ^16, with plate.
(The specimen, described by KROEYER, seems not to have been full grown).
Asellus GEOFFR., SCH^EFFER, LATR. External antennae elongate.
Feet shorter than body. Two abdominal appendages terminated by
two elongated filaments.
Sp. Asellus vulgaris LATR., Oniscus aquaticus L., GEOFFR. Ins. n. PL 22,
fig. 2, DE GEER Mem. p. s. a I'Hist. des Ins. vn. PL 31, DESMAR. Crust.
PL 49, figs, i, 2, TREVIRANUS Verm. Schr. i. Tab. x. figs. 56, 57. This
species is very common in wet ditches, and is almost 3" long. The little
animal passes the winter in the mud. It differs from the genus Oniscus, to
which LINNAEUS united it, in the tail, which is covered above by only a single
shield-like plate, and further, in the greater development of the middle
antennae and in the feet, which increase in length from the head to the tail.
Limnoria LEACH. Four antennae short, subequal. Body cylin-
Sp. Limnoria terebrans LEACH, Trans, of the Linn. Soc. xi. pp. 370, 371 ; a
small animal (i 2'") which perforates the piles and wood-work of marine
jetties, and in a short time may destroy them.
B. First pair of feet short, thick, terminated by a didactylous
Apseudes LEACH. Tail composed of six segments, terminated
by two long filiform appendages of the last pair of feet.
Sp. Apseudes talpa LEACH, Cancer gammarus talpa MONTAGU, Trans, of the
Linn. Soc. ix. p. 98, PL 4, fig. 6 (this figure is copied in the Encycl. method.,
Crust, et Ins. PL 336, fig. -26, DESMAR. Crust. PL 46, fig. 9). MILNE
EDWARDS has given a better figure, Cuv. R. Anim. ed. ill., Crust. PL 62,
Sp. Tanais Cavolinii MILNE EDWARDS, Resume d'Entorn. par MM. AUDOUIN
et EDW. (Encycl. portative, 1829), i. p. 182, PL 29, fig. i, EDW. Hist. not.
des Crust. PL 31, fig. 6.
Comp. on this genus KROEYER, Naturh. TidssTcr. iv. 1842, pp. 167 187.
Tab. n. figs. i22.
Crossurus RATHKE. (Not different perhaps from genus Tanais).
Note. Add genus Rhcea EDW. (Ann. des Sc. Nat. xm. 1828,
pp. 292 296, PL 13 A), unless it be better to refer it to the
Ampliipoda. Genera Eupheus and Olisca Risso, seem to be un-
certain, and require confirmation by more diligent observation.
Perhaps also will have to be placed here amongst the Isopoda, Oniscus
arenarlus SLABBER Natuurk. Verlust. Tab. xi. fig. 4, genus Pterygocerct
LATE., Cuv. R. Ani. 2nd eM. 1829, rv. p. 124.
Family XX. Idoteidea. Tail mostly composed of only three
distinct segments, with last segment large, scutiform. Abdominal
feet branchial ; last pair of feet forming opercular lamina? covering
the branchias beneath. No appendages exsert in the last segment
or at the sides of tail. Antenna? four, very frequently unequal, the
middle approximate. Mandibles destitute of palps.
Anthura LEACH. Four antennae, short, subulate. Body slen-
der, vermiform. Anterior feet incrassated, terminated by an in-
curved hook. Tail with two distinct segments.
Sp. Anthura grant-is LEACH, Oniscus gracilis MONTAGU, DESMAR. Crust. PL
46, fig. 13, MILNE EDWARDS Hist. not. des Crust. PL 31, figs. 3 5.
Idotea FABR. Middle antennas short, with four joints, the last
elongate, cylindrical; external antenna? large, with first five joints
thicker, the rest more slender, running into a terminal seta. All
the feet of trunk terminated by an incurved claw; those of the first,
second and third pairs raptorial, incrassated at the apex and turned
forwards. Branchial feet of tail covered by the last pair of feet
changed into two valves articulated by means of a hinge to the
Sp. Idotea entomon FABR., Oniscus entomon L. (in part), PALLAS Spicil.
Zool. ix. Tab. v. figs, i 6, DE GEER Mem. p. s. a I' Hist, des Ins. vi. PL
32, figs, i 10, KATHKE Beitr. zur Gesch. der Thierwelt, i. Danzig, 1820,
Tab. iv. This animal was found in the Baltic Sea ; it attains a length of
i "9"'. Its two small black eyes are situated at the side of the head in a
round pit, and are not, as is erroneously supposed, simple, but each of them
consists of a group of more than 50 small oval eyes placed close together.
Idotea Lichtensteinii KRAUSS, Sudafrik. Crustaceen, Stuttgart, 1843, Tab.
IV. fig. 4.
Idotea linearis LATR., Stenosoma lineare LEACH, EASTER NatuurL Uitsp.
II. Tab. XHI. fig. 2, DESMAR. Crust. PL 46, fig. 12; from the Baltic, about
To this division also belongs Oniscus viridis of SLABBER, Natuurk. Ver-
lust. PI. 12, figs. 4, 5, which, according to MILNE EDWARDS, forms a
Arcturus LATE. Feet of first pair short, palpiform. Feet of
second, third and fourth pair furnished with long hairs, with last
joint plane, elongate. External antennae of the length of body.
Sp. Arcturus Baffini WESTW., Idotea Baffini SABINE, MILNE EDWARDS Hist,
not. des Crust. PI. 31, fig. i; Arcturus longicornis WESTW., GUKRIN
Iconoyr., Crust. PL 31, fig. i; in this species the first four pairs of feet
stand very remote from the last three.
OKDER VIII, Amphipoda.
Eyes sessile. Four antennae, the two middle inserted above the
lateral. Mandibles mostly furnished with palps. Two pairs of
maxillse and one pair of foot-jaws. Trunk mostly divided into
seven distinct segments, bearing seven pairs of feet not cloven into
two oars. Membranous vesicles for respiration adhering to the base
of some of the feet.
We unite here, after the idea of KROEYER, the Lcemodipoda of
LATREILLE with the order of the Amphipods ; see KROEYER Tids-
skrift, iv. 1843, pp. 490495.
Section I. Lcemodipoda. Posterior part of abdomen or tail
short. First segment of trunk conjoined with head, an oblique
furrow alone on each side indicating the separation; feet of this
segment inserted forwards, beneath the head. Two or three pairs
of branchial vesicles in the anterior part of trunk.
Lcemodipoda from ACUJUOS and Smous; these animals were thus
named because they have two feet under the head, as though at the
throat. They do not swim, but creep on marine plants and animals
in search of food. The posterior part of the body is little developed.
In most the feet are wanting in those rings that carry gill- vesicles,
and conversely the gill-vesicles are wanting on those rings that have
Family XXI. Lcemodipoda. (Characters of the section).
Phalanx I. Gyamea. Body oval, mostly much depressed, with
transverse segments. Antennas with four joints, the last slender;
656 CLASS x.
inferior antennas small. Two pairs of cylindrical branch iae at the
second and third segment of the trunk, in place of feet. Feet
strong, terminated by .an incurved hook, in five pairs. Mandibular
palps none. Females furnished with large lamina? at the base of
branchiae, covering the eggs.
Cyamus LATR. (Species of Oniscus L.).
Sp. Cyamus ceti LATR., Oniscus ceti L., Pycnogonum ceti FABR., PALL. Splc.
ZooL Fasc. ix. Tab. 14, DE GEEE Mem. p. serv. a I'Hist. des Ins. vn. pp.
540 544, PI. 42, figs. 7, 8, TBEVIRANUS Verm. Schr. n. pp. 3 10, Tab. I.
This Crustacean, whose length is about |" and more, lives on Balcma longi-
mana; Cyamus erraticus ROUSSEL DE VAUZ., on the whale of the southern
hemisphere, is an allied species. Cyamus gracilis Rouss. DE VAUZ. is
smaller and more elongate than the other species, and thus approaches to
the form of the next division.
Comp. on this genus, besides the anatomical notices of G. R. TREVIRANUS,
ROUSSEL DE VAUZEME, Ann. des Sc. nat., 2e Se"rie, Tom. i. 1834, Zool. pp.
239 265, PI. 8, 9, and KROEYER NatuurJc. TidssTcr. rv. pp. 474489.
Phalanx II. Caprellina. Body mostly elongate, the length of
the segments surpassing their breath. Feet slender. Branchia3
vesicular at the base of feet Mandibles often furnished with
palp triartieulate. Superior antennas setaceous at the apex,
Caprella LAM. Five pairs of feet, arranged in an interrupted
series, all terminated by a subcheliform hand. Two pairs of bran-
chial vesicles in the second and third segments, in place of feet.
Abdomen very minute, made up of a single or of two segments,
supplied with appendages or rudiments of feet.
Sub-genera : Caprella and ^Egina KROEYER. Sp. Caprella linearis LATR.,
Cancer linearis (L. ?), HERBST Kraliben und Krebse, iv. p. 142, Tab. 36,
figs. 9, 10; Oniscus scolopendrotdes PALL., Spic. ZooL ix. Tab. 4, fig. 15,
Caprella lobata LATR., GU^RIN Iconogr., Crust. PL 28, fig. 2 ; to this or
to Capr. acutifrons DESM. the figure of BASTER, Natuurk. Uitsp. i. PI. iv.
fig. 2, seems also to belong.
Cercops KROEYER. Three pairs of branchial vesicles, the first
pair at the base of the second pair of feet, the rest in place of
feet. Abdomen distinct quinquearticulate.
Sp. Cercops Holbcelli KROEYER 1. 1. Tab. vi. figs, i 13.
Leptomera LATH. (Proto LEACH). Seven pairs of feet, arranged
in a continuous series. Fifth pair of feet shorter, furnished with a
small claw, slightly moveable. Three pairs of branchial vesicles at
the bases of the second, third and fourth pairs of feet. Abdomen
small, uniarticulate, with four appendages, elongate, biarticulate.
Sp. Leptomera pedata, Gammarus pedatus ABILDGAARD, MUELLER Zool.
danic. Tab. 101, figs, i, 2, GUERIN Iconogr., Crust. PL 28, fig. 3. According
to KROEYER Leptomera ventricosa DESMAREST, Squilla ventricosa MUELL.
Zool. dan. is the female of this species. To it belongs also Phthisica
marina SLABBER Natuurk. Verlust. PI. x. figs, i, 2.
The genus Proto of DESMAREST (Crust, p. 276) rests on imperfect observa-
tions, and appears not to differ from Naupredia LATR.
Section II. Genuine Amphipoda. Head distinct from the first
segment sustaining a pair of feet. Segments of trunk mostly fur-
nished with a distinct lateral part (epimeron). Mandibles supplied
with palp. Tail made up of several segments, furnished with bifid
feet. Body mostly compressed, arcuate.
Comp. MILNE EDWARDS Ann. des Sc. nat. xx. 1830, pp. 353 399, and
H. KROEYER Greenland's Amfipoder. Kjobenhavn, 1838. 4to. (printed sepa-
rately from vn. Th. der Kongel. DansTce Videnskabernes Selskabs naiurvid.
leni. Afhandlinger, p. 229, &c.)
Family XXII. Hyperina or Uroptera. Foot-jaws small, not
covering the eibarious organs. Head large. Last abdominal feet
at the apex of tail mostly resembling a flabelliform fin, foliaceous.
Typhis Eisso, EDW.
Sp. Typliisferus EDW. Ann. des Sc. nat. 1. 1. PI. n, fig. 8, GUERIN Iconogr.,
Crust. PI. 27, fig. 8; in the Atlantic near the Canary Islands. This genus
and the preceding are remarkable for their long inferior antennae, which
are bent at three acute angles.
Phronima LATR. Antennse two short. Fifth pair of feet elon-
gate, terminated by a hand broad, didactylous. Tail elongate,
with five distinct segments, the sixth segment coalesced with fifth.
Sp. Phronima sedentaria LATR., Cancer sedentarius FORSK., HERBST Krdbben
und Krebse, n. p. 136, Tab. 36, fig. 8, LATR. Gener. Crust, et Ins. Tab. n.
figs- i> 3 j t^ animal is found in the Mediterranean, where it lives in a
kind of gelatinous keg, open at both ends, probably from a dead Beroe.
VOL. i. 42
658 CLASS x.
See GU^RIN Mm. de la Soc. d'Hist. not. de Paris, iv. pp. 379386,
PI. 23 ; KROEYER Qrcenl. Amfip. pp. 63 68, Tab. iv. figs. 16, 17.
Phrosma Bisso, Dactylocera LATR.
Hyperia LATR. Antennae four. Feet slender, terminated by
an incurved hook. Trunk broad, gibbous above ; tail attenuated.
Lestrigonus EDW., Tyro EDW., Phorcus EDW., Hyperia EDW.,
Sp. Hyperia Latreillii EDW., Ann. des Sc. not. xx. PI. n, figs, i 7,
GU^RIN Iconogr., Crust. PI. 25, fig. 5 ; Hiella Orlignii STBAUS-DURCK-
HEIM, M6m. du Mus. xvm. 1829, PI. 4.
Note. Genus Daira EDW., is distinguished by having only two
short antennae, and by the second pair of feet being didactylous.
Metoecus KROEYER, furnished with four short subulate antennae,
differs from the other Hyperice by the first and second pairs of feet
being shorter and terminated by a didactylous chela. Grcenl.
Amfip. pp. 6063, Tab. iv. fig. 15.
Family XXIII. Gammarina. Foot-jaws large, conjoined at
the base, forming an accessory inferior labium, covering the ciba-
rious organs; cloven anteriorly into two laminae, and on the outside
sustaining an articulate palp. Last caudal feet terminated by
appendages styliform, more rarely foliaceous, not resembling a fin.
Comp. H. KROEYER Nye nordiske Slcegter og Arter, henhorende til Fami-
lien Gammarina. Tidsskrift. iv. 1842, pp. 141 166.
A. Lateral parts of segments of trunk (epimera) moderate, not
covering the bases of feet. Abdominal feet six ; the last terminated
by two small oval laminae.
Corophmm LATR. Two inferior antennae large, thick, pediform.
Sp. Corophium longicorne, Cancer grossipes L., Oniscus volutator PALL.,
Miscell. Zool. Tab. iv. fig. 20, Spic. Zool. ix. Tab. 4, fig. 9, GRONOV.
Zoophylac. Tab. xvn. fig. 7, GURIN Iconogr., Crust. PI. 27, fig. i.
Add genera : Cerapus SAY, A tylus LEACH, Podocerus LEACH, &c.
Comp. MILNE EDWARDS, Hist. Nat. des Crust, in. pp. 58 70.
Genus Erichthonius MILNE EDWARDS, on the authority of KROEYER,
does not differ from Podocerus, but rests on a sexual difference of
the males. TidssJcr. iv. 1842, pp. 163, 164.
B. Four first segments of trunk with epimera large, covering
the bases of feet. Abdominal feet six; the last terminated by
styles, serving with the apex of the incurved tail for jumping.
Body depressed. Anterior either all or the inferior terminated
a filament setaceous, multiarticulate.
Talitrus LATE. Mandibles furnished with a rudiment only of
)alp or destitute of palp. Superior antennae not longer than head,
horter than the pedicle of inferior; inferior elongate*
Genera : Talitrus and Orchestia LEACH.
Sp. Talitrus saltator EDW., Cancer locusta L., PALL. Spic. Zool. IX. Tab. 4,
fig. 7, DESMAR. Crust. PI. 45, fig. 2, Cuv. R. Ani. ed. ill, Crust. PI. 59,
fig. 3. This little animal, about " in size, is very common on the Dutch
coast, where it is constantly progressing in the sand by jumping.
Orchestia is distinguished by the sheer-shaped form of the first and
second pairs of feet; the second pair has a large oval joint at the apex, on
which the moveable curved claw is set; here belongs Orchestia littorea
LEACH, EASIER Natuurk. Uitsp. ii. Tab. 3, figs. 7, 8, DESMAR. Crust.
PI. 45, fig. 3-
Gammarus LATR. (Species from genus Gammarus FABR.).
Mandibles furnished with palp. Superior antennae always longer
ihan the peduncle of inferior, sometimes longer than inferior
Sub-genera : Lysianassa EDW. (Anonyx KROEYER), Alibrotus
EDW. (Lysianassa previously), Phlias GUERIN, Acanthonotus OWEN,
Iscea EDW., Anisopus TEMPLET., Amphitoe LEACH, Gammarus EDW.,
Ischyrocerus KROEYER, Leucothoe LEACH (Lycesta SAV.) and some
others proposed by KROEYER 1. 1.
Sp. Gammarus fluviatilis EDW., Gammarus pulex KOCH, RCESEL Ins. in.
Suppl. Tab. 62 ; KOCH and GERVAIS distinguish this species as Gammarus
Rceselii from Gammarus pulex FABR., DESMAR. Crust. PL 45, fig. 8, Gam-
marus fossarum KOCH in HERRICH-SCH^SFFER Deutschl. Ins. Heft 138,
Tab. i. LINNAEUS has confounded not only these two species, but also
660 CLASS X.
others, as Orchestia littorea, under the name of Cancer pulex, Syst. nat. e
12, i. p. 1055!.
Gammarus pulex FABR., GERV. is very common in ponds. The fema
carries her eggs under the body at the base of the feet, until the youn
emerge. RCESEL saw the animals nibbling at roots, fruits, and other par
of plants which he gave them. Usually, however, they live on anim;
food, and according to DE GEER, do not spare even the bodies of the
companions. They attain a length of about 2". The hinder end of ti
body is always bent downwards. Compare also on this species J. (
ZENKER De Gammari pulicis FABR. Hist, naturali et sanguinis circuit
commentatio. Accedit Tab. ten. Jenae, 1832, 4to, and, on the difference <
the two species, GERVAIS Ann. des Sc. nat. 2e Se'rie, IV. 1835, Zoologi
pp. 127, 128.
OEDER IX. Stomatopoda.
Two compound eyes, placed on a biarticulate moveable petiole
Antennas four, placed nearly in the same horizontal row; interna
long, terminated by two or three multiarticulate setae, externa
mostly furnished at the base with an oval ciliated lamina. Feet o
trunk mostly in seven or six pairs, more rarely eight. Moutl
inferior, often situated between the bases of anterior feet. Branchia
mostly adhering to the caudal feet, more rarely to the thoracic, neve:
covered. Tail mostly terminated posteriorly by a foliaceous pinna
Shell thin, in many almost membranous.
Family XXIV. UnipeUata. Body elongate, narrow. Cephalo-
thoracic shield elongate, often produced over the back of the ante-
rior segments of trunk. Anterior segment of cephalothoracic shield
bearing the middle antennae and eyes, distinct. One pair of max-
illiform feet slender, elongate. Seven pairs of feet in trunk 01
thorax; first pair large, with last joint mostly falcate, dentate in-
ternally; second, third and fourth pairs shorter, approximate to
mouth, terminated by an oval hand and moveable hook; three last
pairs slender, remote, mostly furnished with a styliform appendage.
Of caudal feet six pairs; the first five mostly bearing branchiae of
1 From a passage in the Fauna Suecica p. 246 "habitat ad littora marts vulga-
tissimus" it would seem, that LINNAEUS probably by Cancer pulex had a species in view
different from Gammarus pulex or fluviatilis, perhaps Gammarus locusta FABR. ; that