CIRRIPEDTA. 



441 



Lepadid(f and the Bcdunidce, the alimentary canal consists of a 

 nai-row oesophagus, a saccular dilated stomach provided with several 

 caecal (hepatic) diverticula, an elongated chyle-forming intestine, and 

 a short rectum, which is only sometimes clearly marked off from the 

 intestine (fig. 349). The Rlnzoceplmla (fig. 354, a), which are with- 

 out an alimentary canal, possess root-like processes of the paren- 

 chyma, which ramify in the viscera, especially the liver of Decapods, 

 and absorb from them endosmotically the nutritive "juices (as in 

 Anelasma). 



Special glandular organs, the so-called cement glands (peculiar to the 

 Cirripedia), open on the sucker of the persistent (anterior) antenna; : 

 the animal is fixed by their secretion, and the Rhizocephala alone 

 seem to be en- 



tirelv without v 



r 



them. 



A heart and 

 vascular sys- 

 tem seem to 

 be wanting in 

 all cases. The 

 tubes which are 

 present on seve- 

 ral thoracic ap- 

 pendages o f 

 m: i ny Lepadidce 

 are regarded as 

 branchiae, as 

 are also two 

 plicated lamel- 

 la? on the inte- 

 rior of the 

 mantle of the Balanidce. 



Generative organs. The Cirripedia are, with a few exceptions, 

 hermaphrodite. The testes are branched glandular tubes, and lie 

 at the sides of the alimentary canal (fig. 349, T). The vasa deferentia 

 which dilate into vesicular seininales reach to the base of the cirri- 

 forrn penis, in which they unite to form a common ductus ejacula- 

 torius opening at the point of the penis (IV). The ovaries in the 

 Balanidce lie in the basal part of the body cavity (fig. 348, Or) ; in 

 the Lepadidce (fig. 349) they are moved into the prolongation of the 

 head, which is known as the stalk. The oviducts, according to 



FIG. 350. Alci/i/if lamjias (after Ch. Darwin.) a, Male, very strongly 

 magnified; A', antenna? ; T, testis ; I ', seminal vesicle ; D, redu- 

 plicative of the skin; 0, eye; P, penis. 6, Longitudinal section 

 through female ; F, maxilliped ; Cf, the three pairs of legs ; <3o> 

 ovary. 



