120 KANSAS UNIVERSITY SCIENCE BULLETIN. 



31. Bifidaria armifera Say. 



Typical armifera is found as a fossil, and lives abundantly in the 

 region at the present time. 



32. Vertigo modesta Say. 



Very common in all of the deposits. It is not found living in the state. 

 The second parietal tooth is never developed in these specimens, and the 

 shells are smaller and more cylindrical than the typical modesta. 



Measurements. 



33. Vertigo gouldi Binney. 



Very common in the deposits. The columellar tooth is much heavier 

 and the lower palatal more deeply seated than in the typical form, but we 

 do not hesitate to refer the shells to this species. 



34. Vertigo martini new species. PL, fig. 3. 



Shell light brown ; ovate in outline. Lines of growth faint and ob- 

 lique. Whorls, four and a half, well rounded, and the sutures well 

 impressed. Apex smooth and white and obtusely pointed. Peristome 

 thin and sharp, slightly expanded, and the ends connected across the 

 body whorl by a thin deposit of callous; almost no indentation in the 

 upper palatal wall. Aperture semicircular and with six teeth. Two on 

 the parietal wall, both of which are lamellar in shape, and the angle 

 tooth is the smaller of the two. One columellar in the center of that 

 wall of the aperture. This tooth is bifid, that portion toward the apex 

 of the shell being the larger. One basal tooth, small and nodule-like. 

 Two palatals, both of which are lamellar in shape, the lower one of 

 which is the larger. Variation in a lai'ge series of this species is 

 slight. 



Measurements. 



Type specimens in the U. S. National Museum from the Pleistocene 

 of Phillips county, Kansas. 



This and Vertigo ovata are the only species found in this part of 

 the country with two teeth on the parietal wall. The latter species, 

 however, is much the larger and more ovate in outline. The size of 

 martini is about the same as that of gouldi from the same deposits, but 

 that species is more cylindrical and the angle tooth is never developed. 

 The size is somewhat less than that of Vertigo tridentata, a recent shell 

 of eastern Kansas in which the basal tooth is absent. 



