1869.] 155 [Perkins. 



Lampsilis Rafinesque, 1820. 



Lampsilis radiata Stimpson, Shells of N. E., p. 13 (Agassiz 

 mss.); Morse, Journ. Port.Soc. Nat. Hist., Vol. I, p. 47. Unio radi- 

 atus Lam., An. sans Vert., Vol. vi, p. 535; Gould, Invert. Mass., p. 

 110, fig. 73; De Kay, Moll. N. Y., p. 189. 



Common in Saltonstall Lake and Whitneyville Pond. 



Margaritana Schum., 1817. 

 Sub genus Strophitus Raf. 



Margaritana undulata Lea, Trans. Am. Phil. Soc. Alasma- 

 donta undulata Say, Am. Conch., p. 62, 1819; Gould, Invert. Mass., 

 p. 115, fig. 76; De Kay, Moll. N. Y., p. 198, pi. xv, fig. 227. 



Not common. Occurs in Whitneyville Pond. 



Anodonta Cuvier, 1798. 



Auodonta cataracta Say, Am. Conch., p. 53, pi. lxxi, fig. 4, 

 1816. Anodonta Jluviatilis Lea, Trans. Am. Phil. Soc, Vol. VI, p. 

 .38; Gould, Invert. Mass., p. 117, fig. 80; De Kay, Moll. N. Y., p. 

 203, pi. xl, fig. 358. 



Quite common in rivers and ponds, being much larger in the latter. 



MYTILID^. 



Mytilus Linne, 1758. 



Mytilus edulis (Linn.) Lam., An. sans Vert, Vol. vn, p. 47; 

 Gould, Invert. Mass., p. 121, fig. 82. Mytil us borealis (Lam.) De 

 Kay, Moll. N. Y., p. 182, pi. xiii, fig. 222. Mytilus notatus De Kay, 

 Moll. N. Y., p. 182, pi. xiii, fig. 223 (young). Mytilus pellucidus 

 De Kay, Moll. N. Y., p. 183, pi. xxiv, fig. 256. 



Common in all pools near low water mark, and often very finely 

 marked with blue, green or black. The animal varies in color from 

 white to deep orange; mantle freely open, edge thickened, bordered 

 by a dark line, double, outer part simple, inner from the siphonal 

 openings to about the middle of the ventral side fringed with short, 

 dark, branched papilla".; gills large, long, equal; foot always dark 

 brown, short, thick, obtusely pointed, grooved; palpi triangular, 

 round pointed at the ends, beveled from a median elevated line to the 

 edges, striate within. 



