162 



cles (as seen from below) about equal to the width of the foot at its 

 narrowest part. Foot = 1| length of shell.] 



The specimens to which these notes refer are young ; no adults 

 have yet been found. 



SpHiERiUM SOLIDULUM Pr., found only in the Mohawk Eiver. 

 The shells are almost precisely identical with specimens received 

 from ]\Iichigan. Until the present season very few have been seen, 

 and those only young specimens. The present season, however, 

 affords adults in considerable numbers, in isolated stations. It may 

 be well to remark that this species does not seem to associate largely 

 with Sph. striatinum Lk., which is an abundant species in the river. 

 Each species seems to prefer its own station, but I am not able to 

 state correctly the differences in their habits. This species has prob- 

 ably been introduced from the West. It bears a strong resemblance 

 to Spli. striatinum Lk. {similis Say), differing by being smaller, a lit- 

 tle more angular, and by the absence of strite or sulcations on the 

 umbo. 



Among the shells of this region to which attention has been called 

 heretofore, are a few which seem to need further attention. 



A species of Amnicola is found here, which is, in Thompson's Ver- 

 mont Shells (Adams), referred to Pal. lustrica Say. The shell in 

 question is pupoid in form, the apical whorls having a large angle, 

 and the subsequent whorls a diminished angle, almost cylindrical. 

 The soft parts near the apex, as seen through the shell, are of an 

 orange tint, resembling in that particular some of the Melanidte. In 

 other respects the soft parts are those of the genus Amnicola. This 

 shell has been very widely distributed to my correspondents as 

 '■^Amnicola lustrica Say," but it is probably the same species as de- 

 scribed by Mr. Say as Pal. grana. (See Binney's edition of Say's 

 Works, pp. 110, 111.) I am led to infer from Mr. Say's note to the 

 description of Pal. grana, that his Pal. lustrica is similar to, if not 

 identical with, Valvata pupoidea Gould. 



Among the shells observed this season, it may be well to notice 

 Lymncea gracilis Jay.* On the 18th and 19th of August, I obtained 

 over six hundred specimens of this S23ecies from the outlet of Schuy- 

 ler's Lake, in Otsego County. A few years ago, in company with 



* L. gracilis Jay has been found in the following locations : — 

 Lake Champlain, N. Y. 

 Schuyler's Lake, N. Y. (Lewis.) 

 Little Lakes, N. Y". (dead shells only). (Lewis.) 



Niagara River, N. Y., in a small bay in an island about six miles below Buffalo. 

 (C. T. Robinson.) 

 Lakes near Grand Rapids, Michigan. (McMel & Currier.) 

 Lakes in Grattan, Michigan. " " 



