480 LIMN^ID^, 



curved ; left lip having a thick, narrow layer of enamel, and a 

 rather slight fold midway ; umbilicus not open. Length, seven 

 tenths of an inch ; breadth, four tenths of an inch ; divergence, 

 sixty degrees. 



Found in the southern parts of this State, but I have not met 

 with it near Boston. From New England to Lewis River, 



Its great solidity, and its remarkal}ly broad, corpulent aspect, ap- 

 proximating in character to Paludina, cause it to be easily recog- 

 nized. Its analogue on the European continent is L. pcreger, 

 which, however, differs from this in being a less solid shell, in hav- 

 ing the aperture somewhat expanded, its anterior curve broader, 

 and the fold of the pillar less deep. It comes nearer to L. emar- 

 ginata than to any other American species. 



Limnaea umbilicata. 



Fig. 149. 



Shell small, ovate ; whorls five, rounded, and marked with fine decussating 

 lines ; suture deeply impres.sed ; aperture small, oval ; no conspicuous fold on the 

 columella; umbilicus distinct. 



Limnaa umbilicata, Adams, Bost. Journ. Nat. Hist. iii. 325, pi. 3, fig 14; Sillim. Journ. 



xxxix. 374. — Gould, Iiiv. 218, fig. 149. 

 Limncca caperata, teste W. G. Binney. 



Shell small, short-ovate, apex obtuse ; whorls five, very convex 

 and rounded, slightly oblique, their surface reticulated with fine 



lines, and modified by numerous facets or indentations, ar- 

 Fig. 731. ranged in imperfect revolving series, four or five in number ; 



suture deeply impressed ; aperture small, about half the 



length of the shell, broad oval, not expanded but rather 

 ^kala^' seeming contracted ; outer lip sharp, thickened within by a 



sub-marginal, pinkish colored deposit ; passing backwards 

 on the inner side in a smooth and rounded plate, it joins the pre- 

 ceding whorl at about half the height of the aperture ; a thin glaz- 

 ing of enamel covers the remainder of the inner margin. There is 

 scarcely any approach to a fold on the pillar ; umbilicus large and 

 deep. Length, three tenths of an inch ; breadth, one fifth of an 

 inch ; divergence, sixty-five degrees. 



First collected by Mr. Shiverick at New Bedford. From New 

 England to Michigan (^Binnrij^ ; Jamaica {Aclams^. 



Limncea humilis is of about the same size and general appear- 

 ance ; but its surface is smooth, its whorls more oblique, its mouth 



