66 



LAND AND FRESU-WATER SHELLS OF N. A. [PART 11. 



Fig. 107. 



Limnaa 

 griffithiana. 



species. It is a small and rather slender species, with a regular tapering 

 spire and an aperture about half the length of the shell. The whole shell 

 is covered over with a red coating of the oxide of iron, giving it a rough 

 aspect. (Zea.) 



Limnsea griffithiana, Lea. — Shell ovately conical, thin, substriate, shin- 

 ing, somewhat diaphanous, yellowish horn-color, perforate ; 

 spire rather short; sutures impressed; whirls five, convex; 

 aperture elliptical. 



1, . Hah. Charlotte Lake, Columbia County, New York : Dr. 



( ys. Griffith. My cabinet, and cabinets of Dr. Griffith and Phila- 

 ^ " ' delphia Museum. Diam. .20, length .30 of an inch. 



Rather a small species, differing from most in the form of 

 the mouth, which is nearly a perfect ellipse. In a perfect 

 specimen before me, the aperture within the margin of the lip 

 is thickened by a raised line. The aperture is not quite one-half the 

 length of the shell. I name it after R. E. Griffith, M. D., who seems to be 

 the only person who has observed it. {Lea.) 



Livinsea linshyi, DeKay. — Shell ovate, subventricose ; whirls five, rounded, 

 and rapidly attenuated to the apex; suture deep; aperture oblong-oval, 

 longer than the spire. Pillar-lip with a broad calcareous 

 deposit, the lower portion reverted, and partially covering 

 the umbilicus. Lip thin, forming a shoulder at its junction 

 with the preceding whirl. Body-whirl towards the margin 

 of the outer lip, flattened as in megasoma, and impressed 

 with deep incremental striae which are evident from within. 

 Color : Epidermis chestnut, often obscured by a blackish 

 subvillous pigment. Length, 0.25 ; aperture, 0.1.5. 



This shell has affinities of form with cata>icoj>iuui, and more 

 especially with the variety which is designated by Say as 

 L. pinguis. That variety is, however, represented as having 

 a moderate suture, and the whirls nearly four. I have ventured to im- 

 pose upon it a new name, expressive of my obligations to the Rev. Mr. 

 Linsley, of Stratford, who furnished me with the specimens from his 

 neighborhood. (DeKay.) 



Fig. 109. 



Fig. 108. 



Forms of L. huviUis. 



Fig. 109 gives, at one view, the various forms wliich I have 

 referred to L. hutnilis. 



