268 Mollusca of Middlebury, Vt. and Vicinity. 
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 4} 
whorls! 
L. pallida, nob. This species has been found only at Shore- 
ham. Since it was described, I have found three living speci- 
mens, of a dingy white! 
L. elodes, Say. This species is not very common. 
L. umbrosa, (?) Say. A Limnea is very abundant in many: 
parts of the New England States, which corresponds very nearly to 
Say’s uwmbrosa. 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. plebeia. 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. umbtlicata, 
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. caperata, Say. Although common in this vicinity, this 
species has not been found elsewhere in the eastern states. 
Paysa. 
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 al 
not easily distinguished from the next species, although mature 
specimens differ widely. 
P. heterostropha, Say. This species is common here as ™ 
many other parts of New England. 
P. gyrina? Say. Of this species a very few specimens only 
have been found. Although I have not seen authenticate os iol 
cimens, nor any figure, of Say’s species, they correspond well 
