194 



PROCEEDINGS OF THE ACADEMY OF [May-Oct., 



color, paler buff toward the beaks, a little browner toward the 

 lower margin, the epidermis thin with weak growth lines; under 

 the lens showing radial bands of festooned striae in the middle part. 

 Beaks small, somewhat worn, showing no sculpture. The interior 

 is pale Payne's gray with a rather wide matt border; stained with 

 olive-buff in the cavity toward the beaks. There is a dark, iri- 

 descent triangle at the posterior end of the hinge. 



Length 46, alt. 25.5, diam. 14 mm. 



ToUman, State of Jalisco. Prof. F. Contreras. Type No. 46,197. 



This is a longer shell than Anodonta coardata Anton, differing 

 also in external texture, the wide dull border inside, and the deep, 

 triangular "sinulus" at the end of the hinge. 



Fig. 3. — Anodontites jaliscoevsis. Natural size. 

 Nephronaias aztecorum tolimanensis new subspecies. Fig. 4. 



Differs from N. aztecorum and N. a. chayalensis by the smaller 

 size and lower form, the shell not so wide posteriorly. 



Length 43, alt. 24.3 mm. 



Length 35, alt. 19.3, diam. 11.4 mm. 



Tollman, State of Jalisco. Type No. 46,195. 



A specimen from Rio Grande, Zapotitlan, Jalisco, measures: 

 length 54, alt. 28 mm. 



Fig. 4. — Nephronaias aztecorum tolimanensis. Natural size. 



