PHYSA. 161 



a. PHYSA OSCULANS, Raid. 



Hald. Monog. p. 29, t. 2, f. 13 (excl. f. 11, 12). 



This is certainly a Mexican, not an Indian 

 species, and belongs to the genus Bulinus. 



h. PHYSA MEXICANA, PhiUpin. 



Plate 7, fig. 12. 



Shell imperforate, ovate, inflated, light horn 

 color, thin, dull and not shining, very finely 

 wrinkled ; the apical whorls occupy one-fourth 

 of the entire length ; mouth wide ; columellar 

 fold broadly expanded, almost in the centre of 

 the aperture. — Blnney. 



Length 19, diam. 12 mill. 



This is a true Physa, and to it are referable 

 specimens in the collection of the Academy at 

 Philadelphia as well as in many public and 

 private collections which Jiave been labelled 

 Ph. osculans on account of some resemblance 

 to Haldeman's figures 11 and 12 which are 

 named oscukuis, but really represent lietero- 



fitropha. 



(77) 



