NOTES ON THE MOLLUSKS OF THE COLORADO DESERT,— I. 



By S. Stillman Berry. 



1 .■ — INTRODUCTION. 



Topographically, geologically, and biologically, the Colorado 

 Desert is unique among all the very diverse natural areas of the 

 state of California, only its sister desert to the north, the Mojave, 

 affording a partial parallel. It is likewise one of the most interest- 

 ing of these areas. Nearly every wanderer who has been fated to 

 enter its portals, as even now the present writer, seems to have 

 felt it incumbent upon him to add his mite to the printed record, 

 with the result that an extensive literature of the region is already 

 in existence, and grows apace. Nevertheless, and in face of the 

 fact, this is still in many respects a little known country. 1 



1 In addition to the titles cited in the bibliography, there are a number of 

 works not dealing with the Mollusca which, nevertheless, have such important 

 bearing toward an understanding of the desert and its bionomics, that it seems 

 worth while to include a brief list of a few which have been found particularly 

 helpful in this manner. 

 Abhams, L. 



:10. A phytogeographic and fcaxonomic study of the southern California 

 trees and shrubs. Bulletin New York Botanical Garden, v. (>, p. 300- 85, 

 pi. A-J, 1910. 



:15. The deserts and desert flora of the west. Nature and Science on 

 the Pacific Coast, p. 168-176, pi. 24, San Francisco. 1915. 

 Atsatt, Sarah M. 



:13. The reptiles of the San Jacinto area of southern California. Univer- 

 sity California Publications, Zoology, v. 12, p. 31-50, November, 1913. 

 Bryant, H. C. 



:11. The horned lizards of California and Nevada of the genera Phry- 

 nosoma and Anota. University California Publications, Zoology, v. 9, p. 

 1-84, text fig. A-B, pi. 1-9, December, 1911. 

 Grinnell, J. 



:13. A distributional list of the mammals of California. Proceedings 

 California Academy Sciences, (4), v. 3, p. 265-390, pi. 15-16, 1913. 



:14. An account of the mammals and birds of the Lower Colorado 

 Valley with especial reference to the distributional problems presented. 

 University California Publications, Zoology, v. 12, p. 51-294, text fig. 

 A-I, pi. 3-13, March, 1914. 



:15. A distributional list of the birds of California. Pacific Coast 



(69) 



