360 THE CRUSTACEA. § 298. 
With other Macrura, the testicles consist only of a trilobed glandular mass 
covering the pyloric portion of the stomach, and from which pass off two long, 
very flexuous Vasa deferentia, which are dilated, near their extremity, into 
anearly straight Ductus ejaculatorius. The excretory ducts of the sperm 
are very distinct with the Decapoda, when filled with this fluid, from their 
chalk-white color. With many species, the sperm, as it approaches the end 
of these ducts, is divided into portions, around which capsules or spermato- 
phores are developed. 
These last are usually pyriform, and connected together by a common 
‘band. The external genital organs of the male Decapoda are quite 
varied, although these excretory ducts almost invariably open on the coxal 
joint of the last pair of feet.°? With the Paguridae, and Macrura, the 
male genital orifices are surrounded by a soft sphincter, without any trace 
of a penis, but out of which the Ductus ejaculatorius is perhaps pro- 
truded during copulation.» But with the Brachyura and short-tailed 
Anomura, on the contrary, there are two longer or shorter tubular pe- 
nises, always covered by the tail, which is pressed against the belly. 
With very many Decapoda, the two feet of the first caudal segment are 
transformed into pedicellated processes (secondary penises), the extrem- 
ity of which is sometimes grooved. With some short-tailed Anomura, the 
feet of the second post-abdominal pair take part also in the act of copula- 
tion, and, for this purpose, are prolonged into stalk-like organs. 
Among the Myriapoda, the Glomerina have two testicular tubes extend- 
ing into the abdomen and composed of numerous vesicles partially blended 
together. They unite in the thorax into a common Vas deferens. With 
the Julidae, the testicles have a similar structure, but the vesicles open 
‘separately into the external side of the two Vasa deferentia, which are close 
together, and are connected, in a ladder-like manner, by numerous trans- 
19 With Astacus; see Roesel, loc. cit. Taf. 
LVIII. fig. 9, and Taf. LX. fig. 23; Suckow, loc. 
cit, Taf. X. fig. 15 5; Brandt, Mediz. Zool. Il. Taf. 
XL. fig. 14; Milne Edwards, Hist. d. Crust. Pl. 
XII. fig. 14; and Carus, Erliuterungstaf. Heft. V. 
‘Taf. III. fig. 9. 
20 These spermatophores, first made known by 
Kélliker, are bound together, with Galathea, by 
wamified pedicles ; and with Pagurus, by simple 
filaments ; see Kéliiker, Beitr. zur Kenntniss d. 
Geschiechtsv. &c. p. 9, fig. 21, 22, also, Schweiz. 
Denksch. VIII. p. 52, fig. 32-35. See, also, the 
description which I have given of the spermato- 
phores of Pagurus Bernhardus, in Millers Arch. 
1842, p. 136, note 1. But one must be careful not 
to take, in the testicles of the Decapoda, the mother- 
‘cells in which are developed the radiating cells for 
the spermatophores. 
21 The land crabs make an exception in this re- 
spect, their male genital orifices being situated on 
the last segment of the body ; see Miine Edwards, 
Hist. Nat. d. Crust. I. p. 168, Pl. XVIII. fig. 6 
4Gecarcinus). - 
22 For Astacus, see the figures cited above ; for 
Palinurus, Milne Edwards, Hist. d. Crust. Pl. 
XXIII. fig. 2; and for Hippolyte, Kroyer, loc. 
cit. p. 27, fig. 54, B. f. 
23 There are two very short, and soft penises 
with Mata, Pisa, Cancer, Grapsus, Lupea, 
Gecarcinus, Porcellana, Homola, &c. They are 
Jong, hard, and point forwards with Dromia. 
24 The canaliculated, secondary penises may be 
very easily seen on the first caudal segment of 
Homarus, Nephrops and Astacus; see Roese/, loc. 
cit. Taf. LVI. ; and Carus, Erlauterungstaf. Heft. 
Vv. Taf. III. fig. 12 (Astacus). In this last ge- 
nus, these organs are slightly spiral at their extrem- 
ity. These penises are long, secondary, and con- 
cealed under the tail with the male Brachyura and 
Anomura, with which the majority of the other 
anal feet are wanting ; see Milne Edwards, Hist. 
d, Crust. I. p. 169, Pl. III. fig. 6, 15, 16 (Mata) , 
in this genus the two pairs of anal feet are rudi- 
mentary. This abortion is observed, also, with 
Grapsus, Cancer, Lupea, Ocypoda, Porcellana, 
&e. See the beautiful figures of Savigny, in 
Descript. de lKgypte, Crust. Pl. II.-VII., and 
Cavolini, loc. cit. Taf. II. fig. 10 (Grapsus). With 
Dromia, the two feet of the second caudal segment 
have the form of two long spines. With Homola, 
the same feet are equally pedicellated, but termi- 
nate with a kind of sucker, and, therefore, are un- 
doubtedly auxiliary in the act of copulation. No 
auxiliary organs have been found with Galathea, 
Palinurus, and Scyllarus ; but in the last two 
of these genera the feet of the first caudal segment 
are wholly wanting. With the Caridoidae, the 
copulatory organs are usually absent, and the first 
pair of anal feet does not differ from the others ; 
with Crangon, only, have I found the internal pro- 
longation of these feet highly developed and gla- 
brous; while with the posterior feet, it is very 
small, and, like the external one, very hairy. Ac- 
cording to Joly (loc, cit. p. 43, Pl. III. fig. 20), it 
is somewhat similar with Caridina. Kroyer (loc. 
cit. p. 27, Pl. IL. fig. 54, B. g.) has observed, with 
Hippolyte, between the feet of the fourth pair, two 
short hooked appendages which may be regarded 
as secondary penises, 
