32 PROCEEDINGS OF THE ACADEMY OF [1890. 



lamella, which in most of Vertigos stands very low, in many exactly 

 at the base. 



The other species, V. callosa, has the last whorl relatively less 

 wide, so that the whole shell is of a more oblong shape. In the pal- 

 atal wall, only the part behind the crest is somewhat flattened, while 

 the latter itself forms one unbroken curve from the base up to the 

 suture, and at the moderately projecting auricle there is only a slight 

 flattening. The inferior columellar lamella is at the end of the col- 

 umella, sometimes wanting or a mere trace. Well worthy of notice 

 is a peculiar formation of the surface, the epiconch showing micro- 

 scopic wrinkles or foliations in the direction of the lines of growth 

 producing a peculiar silky gloss, especially on quite fresh examples, 

 and more in some forms than in others. 



The first two examples of this species I obtained in 1885 from Mr, 

 Henry Moores, of Columbus, O., and in 1889 I saw a few more in his 

 collection. In 1887 Mr. E. W. Roper sent me some others from 

 Mass. Last year in different collections I saw quite a number of 

 specimens from different places in New York near the metropolis, 

 under various names : V. gouldii, milium, ovata and also mixed with 

 hollesiana. Of the Ohio examples the color is somewhat lighter, the 

 callus and the lamellse are strong and white, while in the eastern 

 examples they are somewhat thinner and more of the color of the 

 shell. The name callosa was thus mainly derived from the Ohio 

 form (which, however, may be regarded as a variety). 



It is with some hesitation, however, that I now bring it under this 

 head : it is the equivalent of the European V. pygmaea, Drap., of 

 which I have examples for comparison from different countries of the 

 old continent \ The two may even be identical ; at least it would be 

 absolutely impossible to distinguish New York examples from most 

 Europeans. Both forms agree also in certain variations of the aper- 

 tural lamellffi; the inferior columellar lamella may be absent in 

 either, or there may be present a small suprapalatal fold thus ren- 

 dering the number variable from 4-6, the typical, however, being 5. 

 An examination of the soft parts will probably decide the question ; 

 so far I have not had an opportunity to make it. 



On our continent, the range of distribution of the two species — 

 V. gouldii and callosa — seems to be somewhat different, the former 

 having been found in New York, Ohio, Illinois and Colorado, the 

 latter from Massachusetts to Ohio. 



1 Which I have partly collected myself there during a mimber of years. 



