Perkins.] 124 [October 0, 



Rissoa mimita Stimps., Shells of N. E., p. 33. Turbo minula 

 Totten, Am. Journ. Sci., Vol. xxvi, p. 369. Cingula minuta Gould, 

 Invert. Mass., p. 2G5, fig. 171; De Kay, Moll. N. Y., p. 110, pi. iv, 

 fig. 117. 



Very common in a few limited localities. 



Bissoella? eburnea Stimps., Check List. Rissoa eburnea 

 Stimps., Proc. Bost. Soc. Nat. Hist., Vol. iv, p. 14 ; do. Shells of 

 N. E., p. 34, pi. i, fig. 1. 



Not common. 



Cingula Flem. 



Cingula lsevis De Kay, Moll. N. Y., p. ill, pi. vi, fig. 118. 

 Quite common. 



Sub-Family Skeneinj; Stimps., 1865. 



Skenea planorbis Forb. and Han., Brit. Moll. ; Stimps., Shells 

 of N. E., p. 35. Skenea serpuloides Gould, Invert. Mass., p. 247, 

 fig. 189; De Kay, Moll. N. Y., p. 117, pi. xxxii, fig. 303. 



Littoral, occurring with Alexia m?josotis. Not common. 



Sub-Family Hydrobiin^e Stimps., 1865. 

 Amnicola Gould & Hald., 1839. 



Amnicola limosa Hald., Monog., p. 10, pi. i, figs. 5 and 6, 1844; 

 W. G. Binney, Shells of N. A., pt. in, p. 84, fig. 166. Paludina 

 porata Say, Am. Conch., p. 61, 1819. Amnicola porata Gould, In- 

 vert. Mass., p. 229, fig. 157. 



Not common. It occurs in West Eiver and Harris' pond, near 

 New Haven. 



Amnicola porata Hald., Monog., p. 13, pi. i, fig. 8; W. G. Bin- 

 ney, Shells of N. A., pt. in, p. 83, fig. 164; De Kay, Moll. N. Y., 

 p. 88, pi. xxxv, fig. 33. Paludina porata Say, Am. Conch., p. 69, 1821. 



More common than the preceding. Occurs in the same localities. 



Sub-Family Pomatiopsin^e Stimps., 1865 . 



POMATIOPSIS. 



Pomatiopsis lapidaria Tryon, Proc. Phil. Acad., 1862; W. 

 G. Binney, Shells of N. A., pt. in, p. 93, fig. 188; Hald., Monog., p. 

 18, pi. i, fig. 10 Paludina lapidaria Say, Am. Conch., p. 56, 1819. 



Rare. Only a very few specimens found. 



