676 PROCEEDINGS OF THE ACADEMY OF [Sept., 



ON A COLLECTION OF BIRDS AND MAMMALS FROM THE COLORADO DELTA. 

 LOWER CALIFORNIA. 



BY WITMER STONE. 

 WITH FIELD NOTES BY SAMUEL N. RHOADS. 



Early in 1905 Mr. Samuel N. Rhoads made a trip, in the interest? 

 of the Academy of Natural Sciences of Philadelphia, through the north- 

 western portion of Lower California. The birds and mammals, num- 

 bering respectively 258 and 117 specimens, have been submitted to 

 me for identification, and are listed below with such comments as they 

 demand. Mr. Rhoads has added his field notes on various of the spe- 

 cies, which enhance greatly the value of the report. 



The conditions that prevailed during the expedition were peculiarly- 

 unfavorable to collecting of any sort, the rain, cold and high water 

 being almost unprecedented. The accounts of the botanical expedi- 

 tions sent out later by the New York Botanic Garden over the same 

 route taken by Mr. Rhoads give a good idea of the conditions that pre- 

 vailed (see Journ. N. Y. Bot. Garden, May and June, 1905). 



Mr. Rhoads "embarked at Yuma, Arizona, in an open rowboat. 

 February 4, accompanied by Mr. H. E. Wilder, of Riverside, and a 

 guide. They descended the Colorado river as far as the mouth of the 

 Hardy river, which is a slackwater bayou emptying into the Colorado 

 about ten miles above the head of the Gulf of California. The Hard a- 

 was reached February 8, after an exchange of guides at the Colony. 

 where they were fortunate to secure the services of Frank Tejano, a 

 Cocopah Indian. 



"This stream was then ascended as far as the base of the Cocopah 

 range, reaching Bruce's ranch February 15, Pescadoro Slough on the 

 18th and Cocopah Major Mountain on the 19th. Several days were 

 spent at the last point and also just above the mouth of the Hardy. 



"From camp at the base of the Cocopah Knob, after a stay of nine 

 days, the trip was continued overland to Calexico, on the Californian 

 border, which was reached after five days of the most fatiguing drivinu' 

 and marching through the fresh mud and sloughs of the overflowing 

 Colorado. 



