1913.] NATURAL SCIENCES OF PHILADELPHIA. 689 



angle lamella as in A. ododentatum , while of the lip teeth the colu- 

 mellar fold is lacking entirely in one specimen, and is almost com- 

 pletely obsolete in the other. Where the color persisted, the 

 peristome was pinkish-brown or flesh tinted and characteristic of the 

 species. The immature shell measures 21 by 18 mm. in width, 

 with an altitude of 10.5 mm.; the axis is hollow and the mouth 

 possesses no lamellae. 



After the living specimen had been decalcified and sketched (PI. 

 XXXI, fig. 3), it was stained and sectioned, all the study of the various 

 systems being made from reconstructions. The head region was 

 highly contracted, and was not examined to any considerable extent. 

 The unusual length of the mantle cavity, extending from the peri- 

 cardium to the external pore, is reflected in the great length of the 

 mantle arteries and veins, as well as that of the ureter and portions 

 of the reproductive system. Otherwise there are no especially 

 noteworthy features beyond what are indicated in the figures. 



The kidney, placed between the pericardial and body walls on the 

 anterior face of the last fold, presents the usual sac-like appearance. 

 Evidently the reno-pericardial opening is minute, if it exists at all, 

 for a careful study of sections failed to disclose its whereabouts. 

 The ureter, likewise, is difficult to trace throughout a portion of its 

 course. Its external opening is immediately behind that of the 

 alimentary canal, and from this point is readily followed to the 

 region of the pericardium, where it decreases in caliber and passes 

 into a network of blood vessels. Furthermore, the present specimen 

 was slightly damaged in the region of the columellar muscle, thus 

 adding to the difficulty of tracing the connections. It appears that 

 the kidney is in contact, along its inner face, with a slender sack or 

 tube with which the ureter communicates. 



The digestive system (PI. XXXI, fig. 6) requires no especial descrip- 

 tion. A highly intelligent native lad of Baixa Verde is responsible 

 for the statement that Anostoma lives solely on vegetable matter; 

 at all events, several specimens, that he kept for several months, 

 thrived on garden vegetables and moss. He had made no observa- 

 tions on the position of the body in young individuals. 



The description of the reproductive system of A. ringens, as 

 described by Fischer ,2 applies in all essential details to A. depressum^ 

 with the exception of a penis retractor muscle attached to the vas 

 deferens. In A. depressum the external reproductive pore, located 



^Joiir. de Conchyl, 1869, p. 261. 



