14-4 CLASS CRUSTACEA. 



pour into the intestine near the pylorus. The alimentary 

 canal is short and straight. The sides present a range of holes, 

 placed immediately at the insertion of the gills, but which are 

 not discovered until these organs are removed. The breast- 

 piece, seen internally, presents, at least in many large species, 

 some transverse lodges formed by crustaceous laminae, and 

 separated in their middle by a longitudinal crest of tlie same 

 consistence. 



The sexual organs of the males are situated near the origin 

 of the two posterior feet. Two articulated pieces, of solid 

 consistence, in the form of horns, of stylets, or of setaceous 

 antennae, placed at the junction of the tail and thorax, and 

 replacing the first pair of sub-caudal appendages, are re- 

 garded as the generative organs of the males, or at least their 

 sheaths. But according to our observations on various de- 

 capods, they should consist each of a small membranaceous 

 body, sometimes in the form of a bristle, sometimes filiform, or 

 cylindrical, issuing from a hole situated at the articulation of 

 the haunch of the two posterior feet, with the breast-piece. 

 The two vulvae are placed on this piece, between those of the 

 third pair, or at their first articulation, dispositions which 

 depend on the enlargement or diminution of the breast-piece. 

 Copulation takes place belly to belly. The growth of these 

 animals is slow, and they live a long time. It is among them 

 that the largest species are found, and those that are most 

 useful to us as an article of food ; but their flesh is difficult of 

 digestion. The body of some decapods attains a length ex- 

 ceeding three English feet. Their forceps, as is well known, 

 is very formidable, and so powerful in some large individuals 

 as to raise and trip up a goat. They remain habitually in the 

 water, but do not perish directly on being exposed to the air. " 

 Some species even pass a portion of their lives in this latter 

 element, and visit the water only during the season of their 

 amours, and for the puipose of depositing their eggs. They 



