454 CALIFORNIA ACADEMY OF SCIENCES. 



Sialia mexicana. 



Western Bluebird. — Dr. Cooper informs me that he has 

 known a Bluebird to build in a Cliff Swallow's nest. 



Sialia arctica. 



Mountain Bluebird. — Three incubated eggs of this spe- 

 cies were taken from the nest of a Barn Swallow at Lake 

 Tahoe, Cal., by Mr. "Walter Bliss. 



Passer domesticus. 



European Sparrow. — Since the introduction of this pest 

 into our cities, many birds, hitherto common, have left for 

 the suburbs, notably the Cliff Swallows, whose nests were 

 appropriated by the Sparrows. In these cases the limited 

 space compelled the latter to dispense with the usual amount 

 of rubbish, and carry in only a lining of feathers. 



