8 AMNICOLA. 



Extremely numerous on the muddy shores of the rivers Delaware and 

 Schuylkill, between high and low water marks. (Say.) 



Paludina limosa, Sat, Journ. Ac. Nat. Sc. Phila. 1, 125 — lb. Nich. Encycl. 



3d ed. : Binney's ed. p. 61.— De Kay, N. Y. Moll. 88. 

 Paludina porata, Adams, Shells of Vt. p. 2? (teste Hald.). 

 Amnicola porata, Gould, Inv. of Mass. p. 229, f. 157. — Haldeman, Hon. 



10, pi. i, f. 5, 6. 



No. 8960 of the collection is labelled A. peroUusa by Dr. 

 James Lewis, but I know of no published description under that 

 name. 



From Maine and Wisconsin to Virginia. 



Fig. 13. Amnicola galbana, Hald. — Shell conical, smooth, 

 shining, composed of four and a half not very convex whirls, 

 having the lines of growth very fine ; base with a narrow um- 

 bilic ; aperture nearly circular, slightly produced in an angle 

 posteriorly ; labium slightly thickened ; a small portion of it, 

 Amnicola which is rectilinear, in slight contact with the body whirl. 

 galhana. Q^y^^ ^ _ ^ bleached and chalky. 



Occurs fossil in the fresh water newest tertiary deposit in Sus- 

 sex County, New Jersey. {Haldeman.) 



Amnicola galhana, Haldeman, Mon. p. 15, pi. i, f. 9 ; pt. 4, p. 4 of wrapper. 



Amnicola decisa, Hald. — Animal dark colored ; head blackish, get- 

 ting lighter posteriorly ; tentacles translucent, dark on the edges ; an orange- 

 yellow spot at the posterior internal base of the tentacles ; foot yellowish, 

 thickly dotted with black above anteriorly ; anterior edge nearly as dark as 

 the head ; base of the foot thickly dotted with orange on each of the middle, 

 the dotting being more sparse posteriorly, and entirely wanting anteriorly. 

 Shell rather short, conical ; surface smooth, shining (when the dark 

 foreign matter is removed) lines of growth fine ; whirls five, not 

 Fig. 14. very convex, sutured impressed, base slightly perforate ; aperture 

 dilated semicircular, labium slightly concave, in contact with 

 the shell posteriorly, and nearly so throughout its length. 

 Color pale-green, and slightly translucent when the black 

 Amnicola foreign matter is removed. (See fig. 1, on p. 1.) 

 decisa. Inhabits small streams connected with the Susquehanna, and 



has been observed in the Schuylkill by Dr. Griifith. 

 Allied to Paludina similis, Mich., of Europe. A greater portion of the 

 labium lies closer to the shell in this species than in any other here de- 

 scribed, except A. Nickliniana, and A. tenuipes, which are slender species 

 At first view it might be taken for a minute Paludina decisa, and I have 

 named it accordingly. In my correspondence I have hitherto called this 

 species limosa. (Haldeman.) 



Amnicola decisa, Haldeman, Mon. p. 7, pi. i, f. 2, 3. 



