854 THE CRUSTACEA. $ 292, 
the large oviducts of which open at the base of the first pair of feet, near 
the median line of the body.” 
With the Laemodipoda, Isopoda, Amphipoda, and Mysina, there are 
two simple ovarian tubes wound about the digestive canal; these oviducts 
are sometimes terminal, sometimes lateral. The two vulvae are usually 
situated on the internal side of the fifth pair of feet.© The eggs, after 
laying, are always deposited in an incubating pouch, situated beneath the 
anterior extremity of the body, and the walls of which are formed in part 
by from two to five pairs of imbricated, and often concavo-convex lamel- 
lae.® These last are generally bristled on their borders, and are chiefly 
developed at the epoch of procreation, after which they disappear. 
The ovaries of the Squillina differ remarkably from those of the other 
higher Crustacea. They consist of numerous, ramified lobes, filling the lat- 
eral portions of the posterior abdominal segments, and the digitations of 
which extend even into the last and flattened caudal segment. All these 
divisions of each ovary join in a large, long tube, which surrounds the 
digestive canal. The portion of the ovary contained in the three segments 
to which are attached the ambulatory feet, sends towards the ventral sur- 
face, three branches, which join, upon the median line beneath the abdomi- 
nal cord, with those of the opposite side, and form, in the middle of each of 
these three segments, around sinus. These sinuses are connected by longi- 
tudinal anastomoses, and the anterior one is prolonged into a common 
papillary vulva, situated in the middle of the first abdominal segment 
beneath a horny process. 
7 Van der Hoeven, loc. cit. p. 21, Pl. II. fig. 15, 
Pl. III. fig. 1 (Limulus). 
8 There are two ovarian tubes, each continuous 
posteriorly into a short oviduct with Cyamus 
Roussel de Vauzeme, loc. cit. p. 253, Pl. IX. fig. 
9), with dega (Rathké, Nov. Act. Nat. Cur. XX. 
p. 32, Tab. VI. fig. 17), and with Mysis (Frey, 
loc. cit. p. 25). The two oviducts meet in a com- 
mon vulva in front of the anus with Bopyrus and 
Phryzus (Rathké, De Bopyro, &c., p. 19, Tab. I. 
fig. 7, and Noy. Act. Nat. Cur, XX. p. 47). With 
the Asellina, the ovarian tubes are coecal at both 
of their extremities ; the oviducts pass off laterally 
and open in the articulation of the fifth and sixth 
segment of the body (Brandt, Mediz. Zool. IT. p. 
76, Taf. XV. fig. 32). I have observed an analo- 
gous structure in the genital organs of Idothea 
(Miller’s Arch. 1837, p. 434). With Capredla, 
the ovarian tubes are coecal in the same way, but 
they interanastomose by two puirs of short, trans- 
versal oviducts (Goodsir, Edinb. New Philos. Jour. 
July, 1842, p. 184, Pl. III. fig. 2). This author 
adds, contrary to all analogy, that these oviducts 
terminate in two vulvae situated one behind the 
other on the middle of the belly. 
9 The incubating sac of Cyamus and Caprella 
fis composed of four lamellae situated back of the 
dranchiae upon the two footless segments of the 
‘tbody (Roussel de Vauzeme, loc. cit. p. 249, Pl. 
‘VIII. fig. 3, and Goodsir, loc. cit. p. 105, Pl. III. 
fig. 3,10). With Mysis, this cavity contains also 
-only four lamellae covered with stiff bristles and 
attached to the coxae of the last two pairs of feet 
AMiller, Zool. Danic. Tab. LX VI. fig. 1,2 5 Miine 
Edwards, Hist. d. Crust. Pl. XXVI. fig. 8, d.5 
and Rathké,in Wiegmann’s Arch. 1839, I. p. 
199). With Werocila, there are also four large 
Jamellae arising from the coxae of the sixth and 
seventh: pairs of feet. With Idothea, the Aselli- 
na and the Gammarina, on the other hand, the 
five anterior segments of the body have as many 
pairs of ventral lamellae of this kind. With Gam- 
marus, the borders of these ten lamellae are cov- 
ered with long bristles (Zenker, loc. cit. p. 8, fig. 
N.b.). With Cymothoa, the coxae of the first six 
pairs of feet have a semilunar lamella (Milne 
Edwards, Ann. d. Sc. Nat. IIT. 1835, Pl. XIV. 
fig. 2, and Cyclop. loc. cit. p. 784. fig. 436). The 
same is true of Anilocra, judging from Savigny’s 
figure (loc. cit. Crust. Pl. XI. fig. 10-). With 
Bopyrus, and Phryxus, the incubating sac con- 
tains six pairs of lamellae which, in the first of 
these genera, are not wholly superposed (Rathké, 
De Bopyro, &c., p. 6, Tab. I. fig. 5, and Nov. Act. 
Nat. Cur. XX. p. 44, Tab. II. fig. 12). The sixth 
or anterior pair of these lamellae is wanting with 
Cepon (Duvernoy, Ann. d. Sc. Nat. XV. 120, Pl. 
IV. fig. 2), but with the Bopyrina in question, is 
singularly attached to the head. According to 
Treviranus (Verm. Schrift. I. p. 61, Taf. IX. fig. 
52), there are at the bottom of this sac with 
Oniscidae, four short conical processes which se- 
crete a yellowish fluid; but Brandt (loc. cit. II. 
p. 72, Taf. XII. fig. 2, Taf. XV. fig. 33) was una- 
ble to find them, while Rathkeé (loc. cit.) has been 
led to regard as secreting organs also, two fila- 
ments which, with Mysis, are attached to the ven- 
tral wall, and stretch into the incubating sac. 
10 This origin and disappearance of the incubat- 
ing lamellae I have seen very distinctly with Ido- 
thea entomon (Millers Arch. 1837, p. 435). The 
females of Cyamus which Muller (Zool. Danic. 
Tab. CXIX. fig. 16), and Treviranus (Verm. 
Schrift. II. Taf. I. fig. 2) have figured, appear to 
have been individuals whose incubating sac was 
not then fulty developed. 
11 The ovaries of Squil/a are so intimately blend- 
ed in part with the liver, that they may be easi- 
ly confounded with that organ. It is on this 
account that Duvernoy’s figure (Ann. d. Sc. Nat. 
VI. 1836, p. 248, Pl. XV. and VIII. 1837, p. 42, 
Pl. I.) of this organ with this same animal, is not 
