ACADEMY OF SCIENCES. 173 



12 Limnophysa var. G a b b i i , Tnjon. Sacramento Valley 

 Rowell ; Islais Creek, S. F. Co. These specimens agree closely with 

 those I got in Clear Lake, but the difference between this form and the eastern 

 L.catascopium as pointed out by Tnjon, disappears in a large series from 

 all three localities, some of each being twice as large as Mr. Gabb's types. L . 

 A d e 1 i n as Tryon, appears merely a smaller, umbilicate form, but having 

 been first named, must include L . G a b b i i if retained as distinct from L . 

 catascopium. 



13. L. bulimoides Lea. Port Neuf River, Idaho, and Los Angel- 

 es, California, Hemphill. From these widely distant localities, specimens show 

 as little difference as are often found in those of other species irora adjoining 

 counties. 



14 L. B i n n e y i Tryon. Birch Creek, Idaho, Hempktll. Only half 

 as large as types, and much resembling " L. Brownii," Tryon, of 

 Nebraska (see Binney, in L. and F. W. Shells, Vol. II, p. 56, f. 

 86). From the amount of variation observed in L.catascopium and 

 its Pacific analogues, I am inclined, however, to consider these as merely a dwarf- 

 ed variety of L . B i n n e y i , if that is a distinct species. The L. Brownii 

 Tryon, of Ohio, the original type, seems, however, different. (See Amer. Jour, 

 of Conch., Vol. I, 229, pi. 23, f. 15.) 



15 L. obrussa Say. Washington Territory, Birch Creek, Idaho, and 

 San Jose, California, Hemphill. These distant localities give exactly similar 

 specimens of this species, undistinguishable also from Atlantic States types. It 

 is not rare in all northern California. 



16. Physa ampullacea Gld. Owens River, California, Hemphill, 

 These are of the large form figured by Binney in L. and F. W. Shells, 

 p. 79, f. 195, and are very interesting as showing such a permanency of form 

 so far south of latitude 49^, where I discovered them in 1853. Binney's figures 

 may be of a Klamath Lake specimen, and differ some from my types (f. 133), 

 more resembling var. propinqua Tryon, of which Mr. Hemphill also 

 brings a few from near White Pine, Nevada. 



17 Physa var. v i r g a t a Gld. Stockton, Mr. Randall; San Jose, 

 Carlton, San Diego Mines, Hemphill. These all agree very well, but rarely 

 show the extreme shouldered form of the Colorado Desert variety, P. h u m e . 

 r s a Gld. 



18 A p 1 e X u s h y p n r u m Linn. Malade River, Idaho, Utah, 

 Hemphill ; Sacramento River, Museum Cal. Acad. The first are typi- 

 cal, and from the nearest point authentically recorded. The last is a single splen- 

 did specimen, finer than Binney's figure, 259 (op. cit. p. 155) , and may be A. e 1 a t- 

 u s Gld., of Lower California and Mexico. It is possible, however, that it 

 came from the head-waters of the Sacramento River. 



19Gyraulus parvus Say. Cceur dAlene Lake, Montana, Hemp- 

 hill, a very small var., fully distinct from G. vermicularis Gld., which 

 he found as far north as the Dalles, Oregon. 



