81 



time of the beginning of the flooding of the Sal ton Basin. 

 The meteorological conditions that prevailed during his visit 

 were of almost unprecedented rainfall and cold, with ''ice in 

 the coffee-pot" on February 13. 



The writer's observations were made on the last three days 

 of March and throughout the month of April, 1915. Weather 

 conditions were normal, with only one slight shower of rain 

 late in April. 



The combined list of birds is, of course, fragmentary, and 

 based upon insufficient collecting; yet it is undoubtedly worth 

 publishing since it includes names of between thirty-five and 

 forty species not observed by Grinnell during his exhaustive 

 field work in the lower Colorado Valley, February 14 to May 

 15, 1910. The list is presented with the hope of early revision 

 and extension. 



1. Podilymbus podiceps. Pied-billed Grebe. — Observed 



several times on Hardy's Colorado in April. Rhoads 

 collected one specimen at the mouth of the river on 

 February 11. 



2. Larus occidentalis. Western Gull. — ''Very abundant 



on the Colorado and its tributaries" (Rhoads). 



3. Larus argentatus. Herring Gull. — A few observed on 



both the Colorado and the Hardy by Rhoads. 



4. Larus californicus. California Gull. — Observed by 



Rhoads. 



5. Larus heermanni. Heermann's Gull. — Observed by 



Rhoads as far up the Colorado as Yuma. 



6. Larus Philadelphia. Bonaparte's Gull. — One adult, 



black-headed bird was seen at Volcano Lake, April 25. 

 Two examples in a half-starved condition were col- 

 lected by Rhoads in February. 



7. Sterna caspia. Caspian Tern. — Several seen at Volcano 



Lake, April 25. 



8. Sterna elegans. Elegant Tern. — Rhoads writes, "A 



few terns were seen in pairs on all the waters visited, 

 either S. elegans or S. dougalli or both." The former 

 species is common in the Gulf of California, while 

 dougalli is an Atlantic coast tern, and the possibility 

 of its occurrence in the delta need hardly be considered. 



