106 TRUNCATELLINA. 



amples in ray collection by the ribbing being double as coarse. 

 In this it approaches T. costulata Nilss., but naturally has no 

 apertural armature whatever, and a thin peristome, in the 

 full grown stage. 



" The var. costigerella predominates alone in a few places, 

 in others being mixed with typical specimens, and connected 

 therewith by transitions which stand about midway in sculp- 

 ture " (Lindholm). 



Truncatellina tauricola Lindholm. 



Shell rimate, rather small, cylindric, slightly attenuate near 

 the apex, under the lens seen to be very delicately striate ; 

 deep reddish brown, at the apex ashy. "Whorls 6, a little 

 convex, slowly and regularly increasing, separated by an 

 impressed suture, the last whorl slightly ascending. Aperture 

 oblong-subcircular, toothless, the peristome a little reflected, 

 thin. 



Length 2 mm., width 0.8 mm. (Lindholm) . 



Crimea: Tschatyr Dagh (Lindholm). 



Truncatellina tauricola Lindh., Archiv f. Molluskenk. 

 LVIII, 1926, p. 177. 



This form, of which two grown, living specimens were taken, 

 differs from T. cylindrica by the dark reddish-brown color and 

 the extremely fine striation, so that it does not fall within the 

 hitherto known variation amplitude of T. cylindrica. By the 

 two characters mentioned it recalls T. monodon Held {T. 

 striata Grdl.). But a direct comparison of Tyrolese specimens 

 of this species with the Crimean snail shows that the latter 

 has conspicuously more convex whorls and a more deeply 

 impressed suture than in T. monodon, which moreover is one 

 of the toothed truncatellinas (Lindholm) . 



Truncatellina sundleri Odhner. PL 21, figs. 1-3. 



Shell cylindric (with the contours of the right and left 

 sides parallel from the fourth to the last whorl), roundly 

 truncate above, glossy, reddish horn-brown, striate, very 

 narrowly umbilicate. Whorls 6, well rounded, with deep. 



