278 PROCEEDINGS OF THE NATIONAL MVSEVM. vni,.xxiv. 
judging- from the fact that Salton, lying in the depression between 
Dos PahiKis and Indian Springs, is reported to be 250 feet below the 
sea level from actual measurements. These springs and pools, like 
those before named, are surrounded by a luxuriant growth of cane 
grass, tules, etc., and the mesquit, screw bean, and other trees of 
the same order occur in great numbers. Specimens from this place, 
presented by Mr. Orcutt, are contained in the National Museum 
(No. 10-4886). 
Orcutt's discover}' was followed, in 1891, by the detection of living 
examples far to the north in Saratoga Springs, In3'o County, where 
Mr. E. W. Nelson collected several hundred, and a large number were 
collected in a marsh near the springs by Mr. Vernon Bailey. These, 
also, are warm springs, situated in the extreme southeast end of Death 
Valley, near the bend of the Armagosa River, so called (usually noth- 
ing more than a dry wash), at an altitude of 352 feet. The valley is 
the deepest depression in North x\merica, being 480 feet below the 
level of the sea. The geographical range, as. shown by dead or semi- 
fossil examples, is far greater and most extraordinary, extending from 
the shores of Sevier Lake, in middle Utah, as seen by Dr. H. C. Yar- 
row's collection in 1872 ^ (U. S. N. M., No. 73960), to Andocutira, in the 
State of Michoacan, Mexico. From the latter locality examples were 
sent to the National Museum (No. 73908) by Prof. A. Duges some years 
ago, with the following interesting note: 
"Ces moUusques ont ete trouves dans une fourmiliere a, Andocutira, Etat de 
Michoacan. La personne qui me les a reniis pense qu'ils proviennent d'une ancienne 
formation lacustre, aujourd'hui convert par des terrains posterieurs. " ^ 
^Explorations and surveys of Lieut. G. M. Wheeler, U. S. A., V, p. 498; also 
G. W. Tryon, in Proe. Acad. Nat. Science, Phila., May 1, 1873, or to Dr. H. C. Yarrow's 
collection. 
Mr. Call, in his interesting paper on the recent and fossil shells of the Great Ba^^in, 
has not credited this form to either of the ancient lake areas. Attention is directed 
to Bulletin No. 11 of the U. S. Geological Survey (1884), which contains Call's paper 
and the following from Prof. G. K. Gilbert's introductory sketch of "The Quater- 
nary lakes," etc.: 
"In the northern portion of the Great Basin there were two large water bodies; 
the one, Lake Bonneville, covering the Great Salt Lake and Sevier deserts, in west- 
ern Utah; the other, Lake Lahontan, occupying a group of communicating valleys in 
western Nevada." 
The elevation of Pyramid Lake is given by Gannett as 4,890 feet, and Sevier Lake, 
by the same authority, is 4,600 feet above sea level. 
'^With these shells from Professor Duges there was a single example (U. S. N. M. 
No. 73907) of the very rare and little known Valvata humeralis, collected by Thomas 
Say in Mexico, and described by him nearly three-quarters of a century ago in the 
New Harmony Disseminator of Useful knowledge, II, No. 16, August 12,1829. See 
Binney's Bibliography of North American Conchology, 1863, part 1, p. 204. 
The foregoing is the third instance that has come under my observation of 
important though indirect assistance rendered by the lower animals in furnishing 
biological and geological data. 
