692 PROCEEDINGS OF THE ACADEMY OF [DeC, 



Explanation of Plate XXXI. 



Fig. 1 .—Reproductive system of Tomigerus clausus, dorsal view, ag, accessory 

 glands; f, flagellum; g, gonad; r, seminal receptacle; v, seminal vesicle. 



Fig. 2. — Shell of young Anostoma depressum. 



Fig. 3. — Heart and kidney (k) of A. depressum, viewed from underside of spire. 



Fig. 4. — Shell of young A. depressum. 



Fig. 5. — Dorsal view of digestive tract, kidney (k), and pericardium (p) of 

 Tomigerus clausus. Contracted specimen. 



Fig. 6. — Digestive tract of A . depressum viewed from apex of spire. 



Fig. 7. — Reproductive system of A. depressum viewed from apex of shell, ag,. 

 accessory glands; f, flagellum; g, gonad; r, seminal receptacle. 



