May, 1893.] MOLLUSKS OF THE DEATH VALLEY EXPEDITION. 275 



Attention is called to my remarks under Limncea lepida of the pre- 

 vious year's collection (1890), in Proc. U. S. National Museum, Vol. 

 xiv, 1891. 



Lininaea humilis Say. 



Kelton, Utah Territory (Mus. No. 123600), Vernon Bailey, November 7, 1891. 



One specimen in the a dry clay wash, about 100 feet above the level 

 of the lake." 



Lininaea bulimoides Lea. 



Mohave Kiver, near Daggett, Mohave Desert, San Bernardino County, Calif. (Mus. 

 No. 123910), Dr. C. Hart Merriam, March 31, 1891. 



Six examples of this rather rare form, all dead and bleached. 

 Described by the late Dr. Lea, in 1841, from examples collected by 

 Nuttall in Oregon. Since found at many places in the Pacific States 

 and in the Yellowstone region by Hayden's Survey. 



Planorbis lentus Say. 



Ash Meadows, Nevada (Mus. No. 123601), F. Stephens, March 2, 1891. Same region 

 (Mus. No. 123602), Dr. A. K. Fisher, March 15, 1891. Panamint Valley, 

 California (Mus. No. 123603 ), Dr. C. Hart Merriam. Brownsville, Tex. (Mus. 

 No. 123604), William Lloyd. 



Only a few examples of the above are mature or full grown; these, 

 though of rather rude growth compared with specimens from more 

 southerly and less arid regions, are much closer to what Say describes 

 as lentus than to his trivolvis. 



Planorbis liebmanni Dkr. 



Hidalgo, Tamaulipas, Mexico (Mus. No. 123606), William Lloyd, March, 1891. 



Numerous examples of this easily recognizable species. 



Planorbis parvus Say. 



Mohave Eiver near Daggett, Mohave Desert, San Bernardino County, Calif. (Mus. 

 No. 123911), Dr. C. Hart Merriam, March 31, 1891. 



Three examples, bleached. 



Planorbis trivolvis Say. 



Fresno, Calif. (Mus. No. 123605), Vernon Bailey, September 22, 1891. Keeler, Calif. 



(Mus. No. 123615), T. S. Palmer, June 1, 1891. Daggett, Calif. (Mus. No. 



123912), Dr. C. Hart Merriam, March 31, 1891. 



Mr. Bailey's Fresno shells were collected by him in an irrigation 

 ditch. The sj)ecimens, of which there are several, were found living. 

 None of them are adult, being most of them but half grown; at this 

 stage they might be labeled P. tumens Cpr. Palmer's Inyo County 

 examples are dead shells, none adult, being about the same age as 

 Bailey's. All of the above are simply young trivolvis. Dr. Merriam's 

 locality is in the Mohave Desert, near the river of the same name, 

 in San Bernardino County. Some of the examples are nearly typical 

 trivolvis, others exhibit the corpulentus aspect. In both the growth 

 lines are quite conspicuous. The latter are listed herein as P. trivolvis 

 var. (Mus. No. 123913.) 



