268 Mollusca of Middlebury, Vt and Vici7iity. 



in Addison. The most striking character of this species is its 

 elongation with a very few whorls. The specimen in my cabi- 

 net is one inch in length, and in the convexity of the penult 

 whorl only .15 in. diameter. The last whorl is scarcely broader, 

 except across the lips, both of which are expanded. Although 

 nearly seven times longer than its average breadth, it has only 4i 

 whorls ! 



L. pallida, nob. This species has been found only at Shore- 

 ham. Since it was described, I have found three living specie 

 mens, of a dingy white ! 



L. elodes, Say. This species is not very common. 



L. umbrosa, (?) Say. A Limnaea is very abundant in many 

 parts of the New England States, which corresponds very nearly to 

 Say's umbrosa. Some specimens, however, have a more promi- 

 nent columellar fold than is ascribed to that species, and Dr. 

 Gould (Mss.) has proposed for it the name L. plebda. The 

 prominence of this fold is subject to variation, and is not suffi- 

 ciently marked to constitute alone a good specific character. 



L. desidiosa, Say. This species is very common, and is sub- 

 ject to great variation of form, sometimes being elongated and 

 scarcely to be distinguished from L. elodes. Other specimens are 

 short, as in Say's fig. (Am. Conch.) and the upper part of the last 

 whorl is much inflated and more or less shouldered, while the 

 lower part is produced. This variety approaches L. imibilicata, 

 nob., which, however, has the umbilicus larger, and the lower 

 part of the last whorl abbreviated, much inflated, and globular, 

 so that the whole shell has the form of a cone with a hemis- 

 pherical base. 



L. capei'ata, Say. Although common in this vicinity, this 

 species has not been found elsewhere in the eastern states. 



Physa. 



P. ancillaria, Say. This rare species occurs in Lake Cham- 

 plain, and in some ponds in Sudbury. In the lake it is remarka- 

 ble for being sometimes of a deep bay color. The young are 

 not easily distinguished from the next species, although mature 

 specimens difler widely. 



P. heterostropha, Say. This species is common here as in 

 many other parts of New England. 



P. gyritia ? Say. Of this species a very few specimens only 

 have been found. Although I have not seen authenticated spe- 

 cimens, nor any figure, of Say's species, they correspond so well 



