OP CONCHOLOQY. 229 



very constant, as the differences between this and reflexa are 

 the same, in specimens of each, from either of the above 

 localities. 



3. LiMN^A Gabbii, Trjon.— t. 23, f. 2. 



Description. — Shell somewhat oval, with rather short, atten- 

 uated spire, acute at apex; whorls not much rounded; suture 

 well impressed ; body whorl proportionally large, but not in- 

 flated; aperture moderate, semi-oval, a little oblique; colu- 

 mella oblique, narrow, scarcely folded, appressed, covering the 

 umbilicus; surface covered with very close, fine strice. 



Dimensions. — Length 13 millimetres, diameter 7 mill.; length 

 of aperture 8 mill., width 3 mill. 



Habitat. — Clear Lake, California. W. M. Gabb. 



My Cabinet. Cabinet of Mr. Gabb. 



Observations. — This shell very closely resembles L. catasco- 

 pium, Say, but differs in several particulars: the spire is nar- 

 rower and more attenuate, the body whorl is not so much in- 

 flated, the lines of growth are much closer and finer, the colu- 

 mella is different, and the aperture is narrow below, instead of 

 being somewhat broadly rounded, as in L. catascojnum. All 

 the specimens received were the same size as the one figured. 



4. LiMN^A BiNNEYi, Tryon. — t. 23, f. 3. 



Description. — Shell globosely inflated, spire moderate, con 

 vex; apex acute; suture impressed; aperture suboval, outer 

 lip very convex, inner lip broad, folded, sharp-edged, not ap- 

 pressed to the body, and exposing a moderate umbilicus; sur- 

 face shining, densely crowded with very fine striae of growth. 



Dimensions. — Length 19 millimetres, diameter 13 mill.; 

 length of aperture 13 mill., width 6 mill. 



Habitat. — Hell Gate Eiver, Oregon. "W. G. Binney. 



My Cabinet. Cabiuet of Mr. Binney. Cabinet of Smith- 

 sonian Institution. 



Observations. — This shell is nearly related to L. catascopium, 

 Say, but may be distinguished from that species at once by be- 

 ing more globosely inflated, more solid, larger, and by its 

 columella. 



L. emarginata is a larger, longer species, and differs by its 

 truncate columella, exhibited when viewed from the left side. 



5. LiMN^A Brownii, Tryon. — t. 23, f. 15. 



Description. — Shell very like a miniature L. catascopium. 

 Say, being about half the size of that species; whorls 4|, ra- 



