V ° 1 190?^ 1 ] Taylor, Hybridization in Hummingbirds. 291 



[283. Arenaria interpres. Turnstone.— Migrant; rare in near-by- 

 localities (about April 26-May IS.) H. G. Smith records one taken at 

 Sloan's Lake, near Denver, on April 26, 1890 (Nid., Ill, 1896, p. 65), 

 and Cooke records eight seen at Berkeley Lake, near Denver, on May 18, 

 1900. (Birds of Colo., p. 201.)] 



AN INSTANCE OF HYBRIDIZATION IN HUMMING- 

 BIRDS, WITH REMARKS ON THE WEIGHT OF 

 GENERIC CHARACTERS IN THE 

 TROCHILID.E. 



BY WALTER P. TAYLOR. 1 



While collecting in the vicinity of Nicasio, Marin County, for 

 the Museum of Vertebrate Zoology on February 26, 1909, I shot 

 a small hummingbird which I took to be Selasphorus alleni. My 

 attention has been called to the fact, however, that it is a hybrid, 

 probably the result of a cross between Selasphorus alleni and Cahjpte 

 anna. According to Ridgway, it was with little doubt such a hybrid 

 upon which Gould based his description of Selasphorus floresii 

 (Mon. Troch., pt. xxiii, Sept. 1, 1861, pi. 10; Vol. Ill, 1861, pi. 139), 

 from a specimen taken at Bolanos, State of Oaxaca, Mexico. 



There have been to my knowledge previous to this date three 

 definite records only of the taking of this hybrid. One of these is 

 the type of Selasphorus " floresii," taken at Bolanos. The second 

 is a bird found by Walter E. Bryant in a taxidermist's shop in San 

 Francisco (first recorded in 'Forest and Stream,' XXVI, June, 

 1886, p. 426). This specimen was "shot by a boy" near San 

 Francisco, and had been mounted to serve as an ornament on a hat. 

 The third record is that of the taking of a male specimen at Hay- 

 wards, California, by W. Otto Emerson (Condor, III, May, 1901, 

 p. 68). Through the courtesy of the latter I have seen this bird. 

 It is almost identical in coloration and size with the hybrid taken 

 by me at Nicasio, though it resembles Cahjpte anna even more than 

 the Marin County bird. 



1 A Contribution from the University of California Museum of Vertebrate Zoology 



