FAMILY LIMNIAD^E LlMNEA. 73 



LlMNEA EMARGINATA. 



LATE IV. FIG. 77. 



(STATE COLLECTION.) 



L. emarginalus. Say, Jour. Acad. Nat. Sc. Vol 2, p. 170. 



X. id. Id. American Conchology, pi. 55, fig. 1. 



It. id, Haldeman, Monog. Limniades, p. 10, p.. 2, figs. 1-8. 



Descrijition. Shell ovate-conic, thin, translucent and smooth. Whorls five, convex, polished, 

 with minute closely applied incremental lines : suture deep. Apex, when present, acute. 

 Aperture wide, and more than half the entire length. Pillar-lip with the fold obsolete, and 

 reflected in the adult so as to cover the umbilicus : columellar depression deeply emarginate. 



Color. Light ochraceous or rufous brown ; within yellowish white. 



Length, 0-5-1-0. 



Some varieties of this species, according to Haldeman, have the body-whorl marked with 

 revolving divaricate lines, extending to the margin of the outer lip, which is undulated. A 

 boreal species, extending from north of Lake Superior, through Maine, etc. to New-York. 

 I am indebted to Dr. Charles Stillman for specimens from the Mohawk river. 



LlMNEA DESIDIOSA. 



PLATE V. FIG. 78. 



(STATE COLLECTION.) 



Limneus desidiosus. Say, Journ. Acad. Nat. Sciences. Vol. 2, pp. 169 and 378. 



L. id. Id. American Conchology, pi. 55, fig 3. 



L. acuta. Lea, Tr. Am. Phil. Soc. Vol. 5, pi. 19, fig. 81. 



L. casta? Id. Tr. Am. Phil. Soc. 



L. philadetphica. Id. Proceedings of same, Vol. 2, p. 32. 



L, desidiosa. Adams, American Journ. Science, Vol. 40, p. 268. 



L. id. Gould, Inverleurata of Mass. p. 219, fig. 150. 



L. id. Haldemax, Monograph Limniades, p. 31, figs. 1 - 12. 



Description. Shell subconic, somewhat inflated, thin and translucent. Incremental lines 

 rather coarse. Surface with a tendency to form irregular facets. Whorls five, convex, with 

 a deep suture ; body-whorl much the largest. Spire about as long as the aperture. Aperture 

 wide, generally obtuse behind ; edge of lip nearly level. Pillar-lip thick, and not adpressed 

 in front, but having a small umbilical aperture. Columellar fold not very distinct. 



Color. Light chesnut or brownish : margin and submargin often dusky brown. Animal 

 light yellowish grey, darkest on the middle : surface minutely dotted with whitish. 



Length, 0-3-0-5. 



Common between the parallels of 35° and 45°, and from the Atlantic to the Mississippi. 

 I have specimens from various parts of the State, in rivulets and small lakes. 

 Fauna — Pakt 6. 10 



