TRUNCATELLINA. 83 



There is a thick columellar callus, visible on breaking the 

 shell, or in a very oblique view in the mouth, but in the speci- 

 mens seen, the palatal tubercle is too far in to be visible in 

 the mouth. It is a larger, more distinctly striate shell than 

 T. salurnensis. Two measure: length 2.22, diarn. 0.95 mm., 

 and length 1.95 mm. 



Reinhardt has noted that it has no inferior tentacles. 

 When creeping on a horizontal surface the shell is held up- 

 right, like a tower. The merely striate, not ribbed surface is 

 characteristic. The palatal tubercle is at least a half whorl 

 back, not visible from in front, but showing through exter- 

 nally as a light spot. It lives on limestone and dolornitic 

 terrains. The name "monodon" is a misnomer; Held over- 

 looked the deeply placed palatal tooth. 



PI. 8, figs. 15, 16, are copied from Gredler's illustrations of 

 P. striata. 



The original account of Vertigo unidentata, which may be 

 identical, follows. 



[Vertigo] unidentata Studer. Only once I found two 

 specimens in the narrow gorge through which one enters the 

 Gastemthal from Kandersteg, on a fragment of cliff. F. 

 Biguet considers it identical with the mousseron (Pupa 

 minuta, above), but it is once again as large and of darker 

 color (Studer, Naturwiss. Anzeiger d. allgem. Schweizerischen 

 Ges. f. gesamten Naturwiss., May 1, 1820, p. 89). 



This long-lost species was noticed by Hartrnann, Ferussac 

 and Charpentier, without further characterization. Finally 

 0. Reinhardt (Nachrbl. d. Malak. Ges., 1916, p. 131) reviewed 

 its history. He believes that unidentata is perhaps T. mono- 

 don Held, which lives on damp rock faces, while most other 

 species of the genus are ground snails. T. monodon has not 

 been reported from Switzerland, but its occurrence there 

 would be no great extension of its known range. 



16. TRUNCATELLINA UNLVKMATA (Kiister). 



Shell subumbilicate, cylindric, densely costulate-striate, sub- 

 opaque, corneous-yellow. Spire high, the apex broadly conic, 

 truncate. Whorls 7, convex, slowly increasing, joined by a 



