CHAPTEE XV\ 



REPORT 



UPON 



THE COLLECTIONS 



or 



TERRESTRIAL AND FLUVIATILE MOLLUSOA 



MADE IN PORTIONS OF 



COLORADO, UTAH, NEW MEXICO, AND ARIZONA, 



DURING 



THE YEARS 1872, 1873, and 1874. 



BY 



Dr. H. C. YARROW. 



923 



