THE NAUTILUS. 

 A NEW POLYGYRA FROM NEW MEXICO. 



BY W. H. DALL. 



Polygyra miorhyssa n. sp. 



Shell depressed, dark brown with about five and one third rounded 

 whorls, the periphery somewhat above the middle of the outer whorl ; 

 suture distinct, umbilicus small, deep, narrowing rapidly toward the 

 apex ; surface polished, with microscopic revolving strise and fine, 

 small, slightly irregularly distributed oblique transverse ridges; 

 aperture subcircular with a reflected white peristome continued 

 over the body by a thin, translucent callus; within the aperture is 

 small, oblique, white parietal tooth, the reflected peristorne lias an 

 obscure thickening inside the peripheral part, and another more 

 distinct inside the base. Alt. 8.5, lat. 15.5 mm. 



Habitat : Sierra Blanca, Lincoln Co., New Mexico, Rev. E. H. 

 Ashnmn and C. H. Tyler Towusend, from localities between 7,500 

 and 8,500 feet above the sea. 



This species is one of a group comprising the species described by 

 me under the names of Polygyra Ashmuni, pseudodonta, chirica- 

 hnana and rhyssa, all characteristic of high altitudes in the mount- 

 ains of New Mexico and Arizona, and doubtless derived from a 

 single original stock. To this P. Levettei also seems allied, or, per- 

 haps, is conchologically intermediate between the above group and 

 the species like P. Mearnsii. The present species is most nearly re- 

 lated to P. rhyssa, which is a coarser, more rugose and lighter colored 

 shell and usually of larger size. 



DESCRIPTION OF A NEW AMPULLARIA FROM FLORIDA. 



BY WM. H. DALL. 



Ampullaria Pinei n. sp. 



Shell large, thin, with a depressed spire, polished surface and five 

 rounded whorls separated by a narrowly channelled suture; sculp- 

 ture of obscure incremental lines and numerous indistinct low re- 

 volving ridges, variably prominent in different specimens ; besides 

 these there are very fine, sharp, minute, obscurely beaded revolving 

 threads with rather wide interspaces, which are occupied by micro- 

 scopic revolving striae ; this sculpture is often more or less obsolete, 

 but traces of it can usually be found on any specimen ; color of the 



