166 SHELLS OF LOWER CALIFORNT A— STEARNS. vol.xvii. 



Family LimnvEID^. 

 PLANORBIS BICARINATUS, Say. 



Many examples. 



Moatli of Yaqui Eiver (No. 53077, U. S. N. M.), Dr. Edward Palmer; 

 Portland, Oreg. (No. 47000, IT. S. N. M.), and Aiitiocli, Cal., Henry 

 Hemphill, 



It is interesting- to note the wide distribution of this comparatively 

 well-marked form, to which 1 have heretofore and at greater length 

 called attention.* 



Commencing at Cape Elizabeth, Maine; thence westerly through 

 Lake Simcoe, Canada; thence to Manitoba (Miller Christy), and Win- 

 nepeg Lakes {teste Bell), still westerly to Portland, Oreg. ; thence south- 

 erly to the Yaqui River locality near Guaymas, Mexico; thence east- 

 erly through Kansas, Alabama, and Georgia nearly to the Atlantic 

 seaboard by the way of Virginia, the District of Columbia, Pennsyl- 

 vania, New York, and Massachusetts, to the starting point as above 

 given in Maine. 



The west-coast localities are as yet "few and far between," and the 

 number of exami)les limited. It will be observed that there is a great 

 stretch of territory between the Yaqui River locality and the Kansas 

 region, as well as between the Oregon locality and Manitoba. It is 

 not unreasonable to predict or anticipate the detection of P. hicarinattis 

 sooner or later at localities intermediate and connecting, when these 

 vast and sparsely- settled areas are more thoroughly explored or more 

 generally inhabited. 



The occurrence of Helix (Stenotrema hirsuta) near Guaymas is else- 

 where referred to in this paper. 



PLANORBLS CORPULENTUS, Say. 



Several examples. 



Cape St. Lucas, Prof. George Davidson, March, 1873. This species 

 is widely distributed and inhabits an extensive geographical area on 

 the western side of the continent, from the Columbia River in the north, 

 thence easterly to Lake Winnipeg. Binney says ''P. corpulentus is 

 catalogued from Guatemala by Mr. Tristram." 



Family SiPHONARiiDyE. 

 SIPHONARIA LECANILTM, P li i 1 i p p i. 



+var. lyalmata, Carpenter; -\-S. (equilirata, Carpenter; -{-hS.jnca, Sowerby. 

 Abundant. Tres Marias (No. 00380, U. S. N. M.). 

 The typical form in all stages from adolescence to maturity. It is 



* West American Scientist, September, 1889. 



