18 CRUSTACEA. 



ported by a cartilaginous skeleton, is armed internally with 

 five bony and notched appendages, which completes the tri- 

 turation of the aliment. In it, in the moulting season, which 

 arrives near the end of spring, we observe two calcareous bo- 

 dies, round on one side and flat on the other, commonly called 

 crabs' eyes, that disappear after the change is completed, 

 thereby inducing us to believe that they furnish the material 

 for the renewal of the shell. The liver consists of two large 

 clusters of blind vessels, filled with a bilious humour, which 

 they pour into the intestine, near the pylorus. The alimen- 

 tary canal is short and straight. The flanks present a range of 

 holes situated immediately at the insertion of the branchiae, 

 but which can only be seen by removing those organs. The 

 under shell, viewed internally, at least in several large spe- 

 cies, exhibits transverse cells formed by crustaceous laminae, 

 and separated in their middle by a longitudinal range of the 

 same nature. 



The sexual organs of the male are situated near the origin 

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

 consistence, and resembling horns, stylets, or setaceous an- 

 tennae, placed at the junction of the tail with the thorax and 

 replacing the first pair of subcaudal appendages, are regarded 

 as the male organs of copulation, or at least as their sheaths. 

 But, according to our observations on various Decapoda, each 

 of them consists of a little membranous body, sometimes seta- 

 ceous, and at others filiform or cylindrical, that projects from 

 a hole situated at the articulation of the hip of the two poste- 

 rior feet, with the lower shell. The two vulvae are placed on 

 this piece, between those of the third pair, or on their first 

 joint, a disposition depending on the widening and narrowing 

 of the lower shell. Copulation takes place, ventre a ventre, 

 These animals grow but slowly, and live a long time. It is 

 among them that we find the largest and most useful species, 

 but their flesh is not easily digested. The body of some Pali- 

 nuri attains the length of a metre. Their claws are efficacious 

 weapons, and have such power in large individuals, that they 

 have been seen to seize a Goat, and drag it from the shore. 



