54 LAND AND FIIESII-WATER SHELLS OF X. A. [PART 11. 



and a more acute curvature of the inferior portion of the aperture. PI. 

 55, %. 2. {Say.) 



Lirnnaea catascopium, Say, ^'ich. Ency. pi. 11, f. 3 (1817, 1818, 1819) ; 

 Am. Conch. VI, pi. Iv, f. 2 (1834) ; ed. Binney, 45, 211, pi. Ixx, f. 

 3; pi. Iv, f. 2. — Halijeman, Mon. 6, pi. i (1841). — Gould, Iuv. of 

 Mass. 223 (1841).— DkKay, N. Y. Moll. 67, pi. vi, f. 80 (1843).— 

 Mrs. Gkay, Fig. Moll. An. cccx, f. 7. — Kiister in Cli. ed. 2 (Lim- 

 na-us), 46, pi. viii, f. 15-21. — Potiez et Michaud, Gal. des Moll. I, 

 216, pi. xxi, f. 3-4.— Anox. Can. Nat. II, 201, fig. (1857). 



LimnsEa cornea, Valenciennes, Humb. & Bonpl. Rec. 1833, II, 251. 



Lirnnaea pinguis, Say, J. A. N. Sc. V, 123 (1825) ; ed. Binney, 114 (not 

 of DoHRN, Pr. Zool. Soc. 1858, 134). 



Limnxa virginiana, Lamarck, An. s. Vert. VI, 160. — Deshayes in Lana. 

 8, 411 ; ed. 2, III, 416 ; Enc. Meth. Vers, II, 362 (1830).— Delesseht, 

 Rec. des Coq. xxx, 4 (1831). 



Litimwa sericata, Ziegler, teste Haldeman. 



Helix cutascopius, Eaton, Zool. Text-Book, 195 (1826). 



This species is exceedingly abundant in the Delaware River. 

 No, 9207 of the collection shows some of its variable forms. It 

 has also been noticed from. New England to Lewis River, and 

 abounds in high latitudes in the British Possessions. 



Limnasa pinguis, Say, is still represented by authentic speci- 

 mens in the Academy's collection, one being drawn in my Figure 

 83. Say's description is given below. Mr. Haldeman agrees 

 with rae, and DeKay doubtfully places it in the synonymy of L. 

 catascopium. 



Lirnnaea pinguis, Say. — Shell oval, rather ventricose, pale dirty-yellowish ; 



■whirls nearly four, rapidly diminishing to the apex, which is dull fulvous ; 



suture moderate, spire rather more than half the length of the 



Fig. 83. aperture ; aperture large ; la^rum with the inner margin a 



little thickened. Total length eleven-twentieth, aperture rather 



more- than seven-twentieth, breadth seven-twentieth inch. 



Proportionally shorter and much more dilated than other 

 species of the country, with the exception of L. macrostomus, 

 from which it is readily distinguished. It inhabits the Dela- 

 ware and Schuylkill Rivers near Philadelphia, in company with 

 L. catascopium. {Sai/.) 



Limnfisn cornea is referred to L. catascopium by Haldeman 

 and Gould, and also by Ferussac (Bull. Zool. 18.35, 33). I have 

 seen no authentic specimen, but give a translation of the origina' 

 description below. 



Livinffa rornMi, Valexciennes (/. c). — Shell ovate-conic, thin, subpel 

 lucid ; whirls five, lightly striate ; aperture not expanded. 



