§ 292. THE CRUSTACEA. 355 



With the Brachyura, the cephalothorax contains four long ovarian tubes, 

 two anterior, and two posterior. The first wind outwardly over the liver, 

 and are anastomosed by a short transverse canal ; while the second are 

 straight, lie close to each other, and cover the anterior part of the intes- 

 tine. The anterior and posterior tubes of each side unite in a short 

 vagina, and, at their point of junction, open into a pyriform sac, which has 

 been regarded by some as a Bursa copulatrix, and by others as a gland 

 secreting the viscous substance which envelops the eggs, but which, upon a 

 more careful examination of its contents, will be found to be a Recppta- 

 ciilum seminis.'^'-^ The two vaginae open near the ventral median line in the 

 segment which bears the third pair of feet.'^^' With the other Decapoda, — 

 the Anomura and the Macrura, — these sacs, just mentioned, are wanting, 

 while the ovaries themselves are disposed, in general, like those of the 

 Brachyura.^"* But the genera Pagurus and Astacus, alone, form an 

 exception in this respect. In the first, the two ovaries with their oviducts 

 lie concealed principally beneath the dorsal surface of the tail ; while in 

 the second, they are aggregated in a trilobed mass in the pyloric region, 

 from which pass oflF two short oviducts. '^^' The female genital openings 

 are situated, with the Anomura, as with nearly all the Macrura, in the 

 coxal joints of the third pair of feet. *^'"'' 



With the females of all the Decapoda, the feet of all the caudal seg- 

 ments are highly developed and very hairy. They serve to support the 

 eggs which are glued together in clusters by a viscid substance which 

 hardens in water ; these clusters are attached to the bristles or hairs of 

 these feet. But with the Brachyura, and Anomura, these eggs have an 

 additional protection in the tail, which is folded against the body.^''' 



The Chilognatha have only a single long and large ovarian tube, pro- 

 vided with two short oviducts which are narrower, and open externally at 

 two squamous bodies situated on the under surface of the third segment of 

 the body. These two bodies contain two short caeca one of which is 

 dilated at its base into a vesicle, and each pair opens by a common orifice 

 in the vulva. They represent a Receptaculum seminis.^^^^ With the 



perfectly clear. This naturalist has, moreover, re- IG The two vulvae of the crawfish may be seen 



garded a large part of tlie ovaries as venous sinus- in the figures already cited. For those of the 



es, and the white eggs which they contain as coagu- Anomura, which, except with Pasurus, are cuv- 



lated blood. In order to have a general idea uf the ered by the tail curved in front ; see MJ/ne Kd- 



disposition of the female genital organs with these ivard.i, Hist. d. Crust. III. p. 172, PI. XXI. h^ ,->, 



animals, it is only necessary to cast a glance over 18 (Dromia and Remipes), and Arch, du Mu-i 1 : . 



De//e CAwje's figure (Descriz.&c. Tav. LXXXVI. PI. X.XVI. fig. 1, e. ^Lilhodes). But the Cari- 



tig. -1, b. g. g.); it is true that he has represented doidae form an exception in this respect, — their 



them as testicles, but they are perfectly exhibited, female genital openings being situated in the same 



with the exception, however, of the anterior por- places as those of the males, that is on the external 



tion. side of the coxae of the posterior feet ; see A> oyer, 



1-' See Cavolini, loc. cit. p. 138, Taf. II. fig. 3 loc. cit. p. 27, fig. 54, A. f. and fig. 97, B. g. {Hip- 



(Grapsus) ; Milne Edwards., Hist. d. Crust. I. p. polyte). 



170, PI. XII. fig. 12, and Cyclop, loc. cit. p. 784, I'' With Pagurus, the anal feet are developed 



fig. 434 ", Cams, Erlauterungstaf. loc. cit. Heft. V. only on one side of the tail. 



p. 7, Taf. III. fig. 7, and Erdl, Entwickel. d. IS Many erroneous opinions have been enter- 



Hummereies, p. 11 (Maia). tained by Zootomists on the subject of the female 



'3 Cavolini, loc. cit. Taf. II. fig. 2, a. {Grap- genital organs of the Chilognatha. Thus, Trevi- 



sus) ; Milne Edwards, Hist. d. Crust. PI. III. ranus (Verm. Schrift. II. p. 45) with Julus, and 



fig. 4, i. ; and Carus, loc. cit. Taf. III. fig. 8, b. Brandt {Mailer's Arch. 1837, p. 325, Taf. XII. 



(Maia). fig. 8) with Glomeris, tlnnk they have observed 



14 Milne Edwards, Hist. d. Crust. I. p. 171, double ovaries, as is also true of Stein (Muller''3 

 and Davernoy, in Cui;ier's Lecons, &c., loc. cit. Arch. 1842, p. 246, 248) ; but iVeic/JorZ (Phil. Trans. 

 VIII. p. 349. 1842, p. gy, or in Froriep's neue Not. X.XI. p. 161 ; 



15 The internal female genital organs of the craw- see, also, Rijmer Jones, Cyclop, loc. cit. p. 552, 

 fi^h are represented in Roesel, loc. cit. Taf. LX. fig. 315, 316) has noticed only a simple ovarian 

 fig. 24, 25 ; in Suckow, loc. cit. Taf. X. fig. 16; tube with Ju/ws, which I have been able to con- 

 and m Brandt and Ralzeburg^s ilediz. Zool. II. firm ; and as for Glomeris, Brandt (Kecueil, loc. 

 Taf. XI. tig. 15. cit. p. 157) has himself recently perceived the same. 



