272 PROCEEDINGS OF THE ACADEMY OF [1893. 



Those from Tennessee and Alabama show some slight variation. 

 The size is from 1*7— 2*1 mm. gr. diam., 2 - being the average. On 

 some specimens the aperture is not pear shaped as in most, but 

 rather broadly rounded at the left side, as shown in Man. Conch., 

 PI. 33, fig. 44. There is also some difference in the more or less 

 strongly everted peristome. A few specimens from Alabama show 

 a thin lip, but from its appearance it seems to be caused by some 

 disease. 



V. perspectiva can not be mistaken for any other species except 

 parvula, which it resembles in size, coloration and the membranous 

 ribs. But it is sufficiently distinguished by the wider umbilicus, 

 the comparatively narrow last whorl, less expanding and descend- 

 ing in toto to the aperture, which is smaller and not circular; the 

 continuous peristome and the absence of a lip. It holds a singular 

 position also among the species with strongly descending last whorl 

 and transversely elongated aperture by the comparatively more dis- 

 tant and regularly standing membranous ribs, and its small size. 



12. V. cyclophorella Ancey, PI. VIII, f. E. Man. Conch., PI. 33, f. 34-38, PI. 32, f. 29. 



" Resembles temdlabris A. Braun, in its rather slight peristome, 

 and costata in its sculpture. Umbilicus large (about 1 mm. diam). 

 Whorls about 4, the last depressed above. Costulations fine ; aper- 

 ture oblique, nearly round. Diam. 2f, alt. 1 mm." This description 

 has been communicated by Mr. Theo. D. A. Cockerell, with the 

 note : " V. cijclopliorella, collected at West Cliff, Colorado, has the 

 animal entirely translucent, white (except the dark eyes). The 

 liver, seen through the shell, is red-brown." 



As noted, this species has been collected over a wide range of the 

 Rocky Mountains, and is in collections under different names. Col- 

 orado : North Park, Ingersoll collection, received from Mr. J. H. 

 Thomson ; E. A. Barber, Aug., 1874, in collection of the Academy 

 (as V. minuta Say), West Cliff, Mr. Cockerell ; South Park ; Utah : 

 American Fork Canyon, J. D. Putnam; Montana: Helena, Mr. 

 Henry Hemphill (in Acad. Coll.); Idaho ; Wyoming: FortBridger, 

 Dr. Jos. Leidy ; Washington : Walla Walla, Mr. Hemphill ; 

 Nevada : Hamilton (in Nat. Mus. Coll.) ; New Mexico (or Arizona), 

 in Nat. Mus. Coll. 



The above description would be insufficient to characterize the 

 species. By the kindness of Mr. Theo. D. A. Cockerell, who sent 

 me some authentic specimens from Colorado, and Mr. J. A. Thom- 

 son, who presented me his examples, collected by Ingersoll, I was 



