CIRRIPEDIA. 



441 



LepaclidcK and the Balanidce, the alimentary canal consists of a 

 narrow oesophagus, a saccular dilated stomach provided with several 

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

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

 intestine (fig. 349). The Rhizocephala (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 endosinotically the nutritive juices (as in 

 Anelasmci). 



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

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

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

 seem to be en- 

 tirely without 

 them. 



A heart and 

 vascular sys- 

 tem seem to 

 be wanting in 

 all cases. The 

 tubes which ave 

 present on seve- 

 ral thoracic ap- 

 pendages o f 

 many Lepadidce 

 are regarded as 

 branchiae, as 

 are also two 

 plicated lamel- 

 Ite 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 vesiculae seminales reach to the base of the cirri- 

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

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

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

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

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



a 



FIG. 350. AJeippe Jampot (after Ch. Darwin.) a, Male, very strongly 

 magnified ; A', antennae ; T, testis ; V, seminal vesicle ; D, redu- 

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

 through female; F, maxilliped; Cf, the three pairs of legs; Ov< 

 ovary. 



