Elementary text-book of zoology, general Elementary text-book of zoology, general part and special part: protozoa to insecta elementarytextbo00clau Year: 1892 CTERIPEDU. 441 LepadidcB and the Balanidce, the alimentary canal consists of a narrow cesophagus, a saccular dilated stomach provided with several caical (hepatic) diverticula, an elongated chyle-forming intestine, and a short rectum, which is only sometimes clearly marked off from the intestine (fig. 349). The RJiizocephala (fig. 354, a), which are with- out an alimentary canal, possess root-like processes of the paren- chyma, which ra
Elementary text-book of zoology, general Elementary text-book of zoology, general part and special part: protozoa to insecta elementarytextbo00clau Year: 1892 CTERIPEDU. 441 LepadidcB and the Balanidce, the alimentary canal consists of a narrow cesophagus, a saccular dilated stomach provided with several caical (hepatic) diverticula, an elongated chyle-forming intestine, and a short rectum, which is only sometimes clearly marked off from the intestine (fig. 349). The RJiizocephala (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) 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 are present on seve- ral thoracic ap- pendages o f many Lepadidoe are regarded as branchiae, as are also two plicated lamel- lae 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 vesiculse 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 LejKtdidce (fig. 349) they are moved into the prolongation of the head, which is known as the stalk. The oviducts, according to Fig. ZZO.—Aleippe lampat (after Ch. Darwin.) a, Male, very strongly magnified; A', antennae ; T, testis ; V», seminal vesicle ; D, redu- plicature of the skin
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