100 THE CHICAGO ACADEMY OF SCIENCES. 



Sanctcemaricu has a superficial resemblance to Hemphill's occi- 

 dentalis, but differs in lacking the decided shoulder so characteristic 

 of the latter race. Prof. Cockerell (op. cit.) refers sanctcemaricB to 

 his var. compressa (fig. 9, p. 79, Williams "Shell-Collectors' Hand- 

 book.") The figure, however, is quite different from sanctamarice and 

 does not particularly resemble any of our American species. Several 

 European Lymnseas somewhat resemble sanctcemarice. Thus Lymnaea 

 doriana Bourg. (Spic. Mai., p. 100, pi. 12, figs. 9-10) seems similar but 

 the whorls in the American race are not so rounded and the body 

 whorl is more flattened at its posterior extremity. Cockerell's variety 

 expansa (Science Gossip, XXI, p. 179, fig. 121, 1885 non expansa 

 Hald. 1842) is somewhat similar in form. These are all apparently 

 cases of parallel development. 



Lymnaea stagnalis occidentalis Hemphill. Plate XXIII, figures 

 4-5. 



Limncsa stagnalis var. occidentalis Hemphill, Nautilus, IV, p. 26, 1890. — 

 Keep, West Amer. Sh., p. 313, 1904. 



Shell: Quadrangularly inflated, thin, fragile; color light horn; 

 spire short and acute, set abruptly on the body whorl, which is very 

 large and quadrangularly inflated ; suture impressed ; the whorls are 

 considerably shouldered, especially the body whorl; aperture long- 

 ovate, more than twice the length of the spire ; axis strongly gyrate, 

 forming a well-marked plait ; callus closely appressed to the parietal 

 wall ; whorls five ; sculpture of the usual character, and often marked 

 by strong spiral and longitudinal raised ridges, giving the surface a 

 malleated aspect; a small umbilical chink is sometimes present. 

 Length. Breadth. Aperture length. Breadth. 



35.00 21.00 23.00 14.00 mill. Type. 



33.00 21.00 22.00 15.00 " 



35.00 21.00 22.00 14.00 " 



Type : Coll. Henry Hemphill. 



Type Locality: Lake Whatcom, Washington. 



Animal, Jaw, Radula and Genitalia: Unknown. It is ex- 

 ceedingly unfortunate that Mr. Hemphill did not think of the carnivor- 

 ous propensities of Circinaria vanconverensis when he placed the two 

 living specimens of this species in the box with them, because the 

 anatomy of occidentalis is now a desideratum. 



Range: State of Washington, from whence it is only known at 

 present. 



RECORDS. 



Washington: Lake Whatcom, Whatcom Co. (Hemphill). 



Geological Range: Unknown. 



