OP CONCHOLOGY. 221 



Habitat — Tennessee River. Isaac Lea, LL.D. 

 My Cabinet. Cabinet of Mr. Lea. 



Observations. — This species much resembles S. Integra, Say, 

 with which at first I had confounded it. My closer attention 

 was directed to it on account of the difference of color. In- 

 tegra has proportionally a smaller spire, and the whorls are 

 not so well rounded, and, consequently, suture not so well 

 impressed. 



I received a number of specimens from Mr. Lea several 

 years ago. 



6. SoMATOGYRUS PARVULUS, Tryon. — t. 22, f. 10. 



Descri-ption. — Shell very small, globose, rather solid, con- 

 sisting of nearly four convex whorls ; spire small, apex acute ; 

 body whorl well rounded, with aperture ovate, broadly rounded 

 below; pillar lip slightly reflected, but not quite covering the 

 umbilicus. 



Dimensions. — Length •12 inch, diameter "10 inch; length of 

 aperture '085 inch, breadth '075 inch. 



Habitat. — Powell's River, E. Tennessee. S. S. Haldeman. 



My Cabinet. 



Observations. — This shell does not differ materially in aspect 

 from S. Integra, Say; with the same number of whorls, it is, 

 however, much smaller, as well as proportionately more solid. 



7. Hydrobia Californica, Tryon. — t. 22, f. 11. 



Description. — Shell turbinated, consisting of six rather con- 

 vex whorls ; spire elevated, apex acute, suture well impressed ; 

 aperture moderate, ■ ovate ; umbilical region not perforate; epi- 

 dermis minutely striated, polished, dark horn color; opercu- 

 lum thin, shining, dark brown. 



DimensioTis. — Length -13 inch, diameter '09 inch; length of 

 aperture '06 inch, breadth -Ol inch. 



^a6ite(!.— Oakland, and Martinez, California, in brackish 

 water. Wm. M. Gabb. 



My Cabinet. Cabinet of Mr. Gabb. 



Observations. — Resembles somewhat Eissoa minuta, Totten. 

 It is distinguished from all :\\c other West Coast Rissoidde by 

 the absence of ribs. 



