Tchennoj)horns CaroUnensis. 413 



diminishing in size posteriorly (^fig. 2, d,) and terminating in a 

 very short cul de sac, as shown in fig. 5. The intestine 

 (fig. 5, 6, and fig. '^,ff,) wliich is at once distinguished from 

 the stomach by its smaller size, and by coming oflT obliquely 

 from the former near its termination, makes two or three 

 turns throu<zh the substance of the liver and terminates in the 

 anal orifice, at the entrance to the respiratory sack. The 

 liver (fig. 2, e e,) has the same relative size as in the Limaces, 

 forms the posterior portion of the visceral mass, and envel- 

 opes a large portion of the intestinal canal. It consists of 

 two lobes of nearly equal size, each composed of numerous 

 lobules. The biliary secretion is discharged into the stomach 

 near its posterior extremity, by a single duct from each of the 

 principal lobes, (fig. 5, c c.) 



The respiratory cavity presents a very remarkable variation 

 from that of the Limaces, in being attached to the viscera, 

 and in having no connection whatever with the shield. In 

 the Limaces the shield contains two cavities, one of which 

 secretes and contains the calcareous body or rudimentary shell, 

 and the other the organ of respiration, the heart, and kidneys. 



In dissecting the Limaces these two cavities are always 

 raised with the integuments, and the respiratory sack is only 

 attached to the viscera by the different vessels going from and 

 coming to it. The position of the respiratory organ in the 

 animal here described is shown (fig. 1, a,) as it appears 

 when inflated after removing the shield. The respiratory 

 orifice is seen in a cleft on the edjze of the dorsal shield, near 

 its anterior extremity on the right side. The cavity itself 

 consists (fig. 1, a,) of an exceedingly thin delicate, transparent 

 membrane, is of an irregular triangular shape, and terminates 

 posteriorly, on the left side of the visceral mass in a cul de 

 sac. In the concavity of the posterior edge of this sack, are 

 contained the pericardium, with the heart and kidney. As in 

 Limaces and Helices, the heart consists of an auricle and 

 ventricle, the former receiving the circulating fluid from the 

 organs of respiration, and the latter distributing it over the 

 body. The blood-vessels are thin and transparent and not 

 easily traced. 



