CRUSTACEA SEXUAL ORGAXS 



373 



c'L 



cs 



Copepoda. The germ glands are mostly unpaired, and placed symmetrically in the 

 anterior trunk segment dorsally on the intestine. That they were originally double 

 is occasionally apparent. In many parasitic Copepoda (Fig. 247) the germ glands are 

 distinctly paired and not connected by any transverse bridge. In #"/<///'/////" a 

 transverse bridge occurs. The oviducts are paired, and generally branched. Their 



1 nil> are glandular or provided with glandular. in vaginations (cement glands), whose 

 secretion yields the material for the egg sacs. A receptaculum seminis common to 

 the two oviducts is often found. The paired apertures lie in the first abdominal 

 segment (sometimes at its posterior 



edge) either ventrally, laterally, or 

 (rarely) dorsally. The sperm passages 

 are paired or unpaired ; in the latter 

 case they are generally on one side. 

 They are provided with a glandular 

 division, which yields the envelope of 

 the spermatophore, and often with a 

 wider portion functioning as spermato- 

 phore pouch. The apertures in the 

 genital segment are paired or unpaired ; 

 in the second case frequently asym- 

 metrical. 



Argulidse. Two pairs of testes 

 occur in the caudal fin, and there are 



2 vasa defereutia with common sperm 

 vesicle. A glandular tube, coming 

 from the anterior part of the body, 

 enters each vas deferens. The two 

 v:isa deferent ia unite under the intes- 

 tine into a common ductus ejacula- 

 torius, which opens at the end of the 

 last thoracic segment on a papilla-like 

 ] projection. The ovary is unpaired, 

 and even from its first appearance 

 asymmetrical ; it lies in the thorax. 

 The oviduct first appears paired, but 



it is afterwards atrophied on one side, 



FIG. 24S. Longitudinal section through a 



and emerges at the base of the caudal mature sacculina carcini externa, at right angles 

 fin. Two receptacula seminis, entirely to t he plane of symmetry (after Delage). co, Cloacal 

 separate from the female genital appar- aperture ; sp, sphincter of the <-li >u<-a (.?) ; g, gangliun ; 

 atus occur on the under side of the ' outer integumental lamella, covering the brood 

 1 , ,, cavity ; nt, female genital atrium, into which the un- 



paired portion (uov) of the ovary and the cement 



Cirripedia. The strikingly lobate glands (cd) enter ; in, brood cavity, sin. mi empty to 

 ovaries are paired in the Balanidcc, the left, with egg sacs (es) containing the developing 

 and lie deep down in the shell ring eggs to the right; #00, the paired part of the ovary; 

 (Fig. 207, p. 304) in that part of the "' inner inte^ntel lamella cov-rinK the body 



proper or visceral sac ; p, stalk entering the aperture 



body cavity which extends into the 

 mantle fold. 



the sheU carapace (cp) of the host ; w, attachments 



In the Lepadidic (Fig. of the roots on the stalk ; da, central lacuna of the 

 205, p. 303) the ovaries, which are to stalk continued into the lacunse of the outer inte-u- 

 some extent united, lie in the anterior mental lamella ' the roots ' etc " ^presenting the body 



IT <- c AT i j 11 i cavity; , testes. 



cephalic portion ot the body called 



the peduncle. In both the Balanidcc and the Lepudidn- the terminal division of the 

 oviduct emerges on a projection on the basal joint of the anterior pair of tendril-like 



