STOMAPODA. 79 



the liver and intestine receives the venous blood which is 

 poured into it from all parts of the body. On the level of 

 each segment to which the foot-jaws and branchiae are attach- 

 ed, it gives off a branch on each side, running to that part of 

 tlie branchisB which is situated at the base of the correspond- 

 ing foot-jaw. The parietes of these vessels appear to the 

 above mentioned gentlemen to be smooth and continuous, but 

 formed by a layer of lamellated cellular tissue glued to the 

 neighbouring muscles, rather than by a membrane proper; 

 these vessels also appeared to them to communicate with each 

 other near the lateral margin of the annuli, but they could 

 not positively affirm it. The afferent or internal vessels of 

 the branchiae, which in these Squillse form tufted bunches, 

 are continuous with the branchio- cardiac canals, are no longer 

 lodged in cells, pass between muscles, turn obliquely over the 

 lateral part of the abdomen, reach the anterior margin of the 

 preceding ring, and terminate on the superior surface of the 

 heart near the median line, one partly mounting on the other. 

 The medullary cord, exclusive of the brain, presents but ten 

 ganglions, of which the anterior furnishes nerves to the mouth, 

 the three following, those of the six natatory feet, and the last 

 six, those of the tail. Thus, although the four last foot-jaws 

 represent the four anterior feet of the Decapoda, they never- 

 theless form a part of the organs of raanducation. The sto- 

 mach of these Crustacea — Sq'uillae — is small and has but a few 

 very small teeth(l) near the pylorus. It is followed by a 

 straight and slender intestine which extends along the whole 

 abdomen, accompanied on the right and left by glandular lobes 

 which appear to supply the want of a liver. A ramous ap- 

 pendage adhering to the inner base of the last pair of feet 

 appears to characterize the male. 



The teguments of the Stomapoda are thin, and in several, 

 nearly membranous or diaphanous. The shell is sometimes 

 formed of two shields, of wliich the anterior corresponds to 

 the head and the posterior to the thorax, and sometimes of 



(1) They form two ranges of transverse and parallel striae. 



