n 



I 



360 THE CRUSTACEA. "J. 293. 



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 defere?itia, which are dilated, near their extremity, into 

 a nearly stniight 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 tli;"- 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. '^> ij 



With very many Decapoda, the two feet of the first caudal segment are | 



transformed into pedicellated processes (secondary penises), the extrem- I 



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.*-^' f 



Among the Myriapoda, the Glomerina have two testicular tubes extend- 

 ing into the abdomen and composed of numerous vesicles partially blended i 

 together. They unite in the thorax into a common Vas deferens. With i 

 the Julidae, the testicles have a similar structure, but the vesicles open 

 separately into the external side of the two Yasa deferentia, which are close 

 together, and are connected, in a ladder-like manner, by numerous trana- 



I'J With Astacus ; see Roese/, loc. cit. Taf. V. Taf. III. fig. 12 (Astacus). In this last ge- 



LVIII. fig. 9, and Taf. LX. fig. 23 ; Suckow, loc. nus, these organs are slightly spiral at their extrem- 



cit. Taf. X. fig. 15 ; Brandt, MeJiz. Zool. II. Taf. ity. These penises are long, secondary, and con- 



XI. fig. 14 ; Milne Edwards, Hist. d. Crust. PI. cealed under the tail with the male Brachyura and 



XII. fig. 14 ; and Cams, Erlauterungstaf. Heft. V. Anomura, with which the majority of the other 

 Taf. III. fig. 9. anal feet are wanting ; see Milne Edwards, Hist. 



20 These spermatophores, first made known by d. Crust. I. p. 169, PI. III. fig. 6, 15, 16 (Maia) ; 

 Kolliker, are bound together, with Galathea, by in this genus the two pairs of anal feet are rudi- 

 ramified pedicles ; and with Pasurus, by simple mentary. This abortion is observed, also, with 

 filaments ; see Kolliker, Beitr. zur Kenntniss d. Grapsus, Cancer, Lupea, Ocypoda, Porcellana, 

 Geschlechtsv. &c. p. 9, fig. 21, 22, also, Schweiz. &c. See the beautiful figures of Savis'ni/, in 

 Denksch. VIII. p. 52, Hg. 32-35. See, also, the Uescript. de I'jSgypte, Crust. Pi. II.-VII., and 

 description which I have given of the spermato- Cavo/ini, loc. cit. Taf. II. fig. 10 (Grapsus). With 

 phores of Pasurus Bernhardus, in Mailer's Arch. Dromia, the two feet of the second caudal segment 

 1842, p. 130, note 1. But one must be careful not have the form of two long siiines. W' ith Homola, 

 to take, in the testicles of the Decapoda, the mother- the same feet are equally pedicellated, but termi- 

 cells in which are developed the radiating cells for nate with a kind of sucker, and, therefore, are uu- 

 the spermatophores. doubtedly au.xiliary in the act of copulation. No 



21 The land crabs make an exception in this re- auxiliary organs have been found with Galathea, 

 spect, their male genital orifices being situated on Palinurus, and Scyllarns ; but in the last two 

 the Jast segment of the body ; see Milne Edwards, of these genera the feet of the first caudal segment 

 Hist. Nat. d. Crust. I. p. 168, PI. XVIII. tig. 6 are wholly wanting. With the Caridoidae, the 

 {Gecarcinus). copulatory organs are usually absent, and the first 



2-' For Astacus, see the figures cited above ; for pair of anal feet does not differ from the others ; 



Palinurus, Milne Edwards, Hist. d. Crust. PI. with Crang'on, only, have I found the internal pro- 



XXIII. fig. 2 ; and for Hippolyte, Kroyer, loc. longation of these feet highly developed and gla- 



cit. p. 27, fig. 54, B. f. brous ; while with the posterior feet, it is very 



23 There are two verj' short, and soft penises small, and, like the external one, veiy hairy. Ac- 

 with Mala, Pisa, Cancer, Grapsus, Lupea, cording to Joly (loc. cit. p. 43, PI. III. fig. 20), it 

 Gecarcinus, Porcellana, Hoi. ola, kc. They are is somewhat similar with Car/rf/no. h'ri/yer Qoc. 

 long, hard, and point forwarils with Dromia. cit. p. 27, PI. II. fig. 54, B. g.) has observed, with 



24 The canaliculated, secondary penises may be Hippolyte, l>etween the feet of the fourth pair, two 

 very easily seen on the first cau<lal segment of short hooked appendages which may be regarded 

 Homarus, Nephrops and Astacus; see Roese/, loc. as secondary penises. 

 cit. Taf. IjVI. ; and Carus, Erlauterungstaf. Heft. 



