334 



CRUSTACEA. 



ries are derived form the above-mentioned simple heart. A consider- 

 able trunk (Jig. 157, g,) Fig. 158. 

 goes from its anterior 

 extremity to supply the 

 eyes, antennae, stomach, 

 and neighbouring or- 

 gans : another, the he- 

 patic (i), which is 

 sometimes double, sup- 

 plies the two lobes of 

 the liver : a third large 

 vessel (A) supplies the 

 abdominal or caudal re- 

 gion : and a fourth, the 

 sternal , derived from 

 the posterior apex of 

 the heart, bends down 

 to the ventral aspect of 

 the body, where it di- 

 vides ; the posterior di- 

 vision (/, /) supplying 

 the lower parts of the 

 abdomen, while the an- 

 terior and larger divi- 

 sion (m) gives off 

 branches to the legs 

 and foot-jaws (w, n, n, 

 w); it likewise furnishes 

 other vessels (o, o, o, 

 o) which are distribut- 

 ed through the bran- 

 chiae. 



The venous system 

 is made up of large and 

 delicate sinuses that 

 communicate freely 

 with each other, and 

 receive the blood from 

 all parts of the body. 

 Those of the dorsal re- 

 gion are represented in the annexed figure: (.fig. 158), a large 



