176 BULLETIN OF THE 



P. strigosa Cooperi, form elevafa, Ckll. Delta Co. 



P. strigosa Cooperi, form major, uov. Shell with diam. 25 mm. Near head 

 of North Mam Creek, Mesa Co., Sept. 14, 1887. 



P. strigosa Cooperi, var. minor, Ckll. Near Egeria, Routt Co., abundant. It 

 is quite a distinct local race. 



Pristiloma, Ancet. 



Animal as in Patula. 



Shell small, imperforate, horn-color, shining, many whorled ; spire de- 

 pressed conic ; aperture sometimes armed with radiating, rather crowded, 

 palatal lamellae. 



Northern and Arctic North America. 



Tj'pes: Zonites Stearnsi and Lansingi, Bland. 

 Formerly Pristina, Ancey, and Anceyia, Pilsbry, preoc. 



Jaw low, wide, slightly arcuate, ends little attenuated, blunt, with numer- 

 ous crowded broad ribs, denticulating either margin. 



Lingual membrane with tricuspid centrals, bicuspid laterals, aculeate mar- 

 ginals, as in Zonites. 



Separated from Microphysa by the ribbed jaw combined with the lingual 

 membrane of Zonites : a very unusual occurrence. 



Pristina Lansingi, Bland. 



Plate III. Fig. 6. 



I give a better figure of this species. 



Pristiloma Stearnsi, Bland. 



Vol. v., figures in text. Suppl., Plate I. Figs. N (dentition) and O (jaw). 



Shell minute, imperforate, globose conic, striate, shining, horn-colored ; 

 suture impressed ; whorls 7, regularly increasing, the last not descending, very 

 globose, swollen below, excavated closely around the imperforate umbilical 

 region; aperture rounded ; peristome simple, acute. Greater diameter 4 mm., 

 lesser 3| ; height 2| mm. 



Zonites Stearnsi, Bland, Ann. N. Y. Lye, XI. 74, Figs. 1, 2 (1875). 

 Microphi/sa Stearnsi, W. G. Binnev, Terr. Moll. V., figs, in text; Suppl., Plate II. 

 Figs. N (dentition) and O (jaw). 



Astoria, Portland, Oregon ; Olympia, Washington ; Alaska. A species of 

 the Oregonian region. 



It is larger, more elevated, and more distinctly striated than Lansingi, with 

 wider, more rounded, unarmed aperture. 



