Ferkins.] 132 [October 6, 



bidentata Gould, Invert. Mass., p. 197, fig. 130; De Kay, Moll. 

 N. Y., p. 57, pi. v, fig. 92. 



Very abundant on walls near high water, in salt marshes, on piles 

 of bridges, and other places above low water. It varies greatly in 

 form and color. Animal dark brown or fuscous; tentacles cylindri- 

 cal, a little tapering, not long; eyes on inner bases; foot oblong, 

 rounded and notched behind; edge scalloped slightly, divided into 

 three lobe-like segments; the first narrow, sub-crescent-shaped, 

 notched in front; the second broader, trapezoidal; the third much 

 the largest, straight in front, rounded behind and notched. 





MEASUREMENTS. 





gth of shell 



8.6 mill. 



Breadth 4.6 mill. 



" 1st segment of foot .8 " 



3.2 " 



2d 



" 1.6 " 



" 4.2 " 



3d 



" 5 (i 



2 " 



" tentacles 



2.2 " 



LIMNEUXE. 





Lymnophysa Fitz., 1833. 



Lymnophysa desidiosa Morse. Journ. Port. Soc. Nat. Hist., 

 Vol. i, p. 41. Lymncea desidiosa Say, Am. Conch., pp. 66, 130, 211, 

 pi. lv ; Gould, Invert. Mass., p. 219, fig. 150 ; Hald., Monogr., p. 31, 

 pi. x; Binney, Shells of N. A., pt. n, p. 48, fig. 68. 



Common in ponds, especially in a small pond by the roadside near 

 the Lighthouse. 



Lymnophysa umbrosa Tryon, Am. Journ. Conch., Vol. in, p 

 250. Lymnophysa elodes Morse, Journ. Port. Soc. Nat. Hist., Vol. I, p 

 41. Lymnceus umbrosa 'Say, Am. Conch., p. 168, pi. xxxi; De Kay 

 Moll. N. Y., p. 68, pi. iv, fig. 76. Lymnceus elodes Say, Am. Conch, 

 pp. 66, 188. Lymncea elodes Gould, Invert. Mass., p. 221, figs. 146 

 147. Lymnceus fragilis De Kay, Moll. N. Y., p. 68, pi. iv, fig. 76 

 Lymncea palustris (pars) Binney, Shells of N. A., pt. n, p. 44 

 fig. .60. 



Common in most ponds. I have followed Mr. Tryon in placing 

 the species commonly called L. elodes under L. umbrosa, as that seems 

 to me to be its proper place. 



