222 PROCEEDINGS OF THE ACADEMY OF [Mch., 



Microcermnus comprises the species formerly referred to Macro- 

 ceramus in works on snails of the United States. These, with their 

 Antillean relatives, prove to have no near relationship to true Macro- 

 ceramus, which belongs to a different subfamily, the Urocoptince, very 

 unlike the Microceramince in dentition. 

 Microceramus texanus (Pils.). PI. XXVI, figs. 19-21. 



A species of the hill country inhabited by Holospira goldfussi, with 

 which it is found. It was originally described from New Braunfels, 

 Comal county, but the range has been extended both north and south 

 by Mr. Ferriss and myself. vSpecim^ens were taken in the drift of the 

 Hondo river, two miles north of Hondo, Medina county; in Comal coun- 

 ty, on the rocky, wooded hillside above the head fountains of Comal 

 creek, near New Braunfels, and along the Guadalupe river, some 

 miles above (figs. 19-21). These last are the largest and best developed 

 shells, but vary in size : 



Length 10.5, diam. 3.5 mm. 

 8.3, " 3.5 " 



a CO u o n 



The average is about 9 x 3.5 mm. 



In the debris of Sinking creek, near San Marcos, Hays county, they 

 are smaller : 



Length 8, diam. 3.1 mm. 

 7.3, '' 3 " 



M. texanus is closely related to M. mexicanus (v. Mart.), a species 

 extending from the State of Vera Cruz to Nuevo Leon and Tamaulipas, 

 and to M. floridanus of Florida. The areas of the three are now widely 

 separated. 



Family HELIOID^ 



The following genera of HcUcidce are represented in Arizona and New 

 Mexico : 



Ashmunella Pils. and Ckll. Thysanophora Strebel. 



Sonorella Pilsbry. Polygyra Say. 



Oreohelix Pilsbry. 



The first three of these, though degenerate in their reproductive 

 organs, are believed to belong to the Belogona euadenia of my classifi- 

 cation of Helices, and are therefore more nearly related to the Califor- 

 nian and ^lexican Helices than to those of eastern North America. 



Thysanophora is represented by two species, noticed below. 



The only Polygyra yet reported from New Mexico or Arizona is Poly- 

 gyra triodontoides Bid., which has been reported from South Spring 



