112 AMERICAN JOURNAL 



ble twist, reflected over and nearly covering the umbilicus. 

 Light brown or horn color, shining, tip of spire and interior 

 margin of labrum colored dark bluish -purple. 



Dimensions. — Length 19 mill., diam. 9 mill. 

 Habitat. — Weatogue, Hartford Co., Conn. Dr. S. Shurtleflf. 

 My cabinet. Cabinet of Isaac Lea. Cabinet of Dr. Shurt- 

 leff. 



Observations. — The circumstances under which this and the 

 following species were found are so peculiar that it is with 

 o-reat hesitation that I have ventured on a description of either 

 of them. That new species of these shells should exist unde- 

 tected in sections of the United States which have been so well 

 explored by assiduous naturalists, would be surprising; but in 

 the present instance the almost irresistible supposition is, that 

 these species are of very recent origin, in fact, contemporaneous 

 with that of the body of water which they inhabit. I have 

 looked in vain for some evidence upon the specimens them- 

 selves of the effect of some strong local influence. The species 

 are so distinct that they afford no clue to a possible derivation 

 from others. 



In conclusion, I present the following interesting particu- 

 lars : — 



Extract from a letter from the late Dr. S. Shurtleff to Isaac 

 Lea, Esq., dated Weatogue, Hartford Co., Conn., November 

 22, 1865. 



"In the summer of 1860 I made an excavation some two 

 rods below a spring that flows about eight months in the year. 

 The spring comes from a neighboring hill. The overlying 

 rock is New Red Sandstone. From the time of the excavation 

 until the summer of 1864 there was water in the artificial pond. 

 It was dry in 1864, but I did not examine for shells, as before 

 the excavation I had repeatedly examined the spring, but 

 never found shells of any description. 



"After m}^ return from Pennsylvania in September, 1865, 

 accidentally crossing the pond, which was dry, I noticed quan- 

 tities of shells clustured in the hollows. I gathered a few and 

 laid them by for leisure examination ; and when I came to 

 look at them again, I found L. umbrosa, as I supposed, as well 

 as a nondescript species. I immediately went to the pond 

 and secured all the Lymnseans I could find — some alive and 

 many dead ; and, fearing the dry season would destroy them 

 all, I put many of the living shells into another pond I have 

 since made, that will never dry up. I may have collected 50 

 specimens of L. umbrosa? and of the other specimens a half 

 pint. 



