446 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



The race of this species that is found in Texas and northeastern 

 Mexico is known as Amazilia y. chalconota. Other races occur in 

 southern Mexico and in Yucatan. 



While apparently not regularly migratory, nevertheless it appears 

 that those birds breeding in the Rio Grande Valley leave in October 

 for winter quarters in southern Tamaulipas and Veracruz, returning 

 in April. 



Egg dates. — Texas: 30 records, March 24 to July 16; 15 records, 

 May 9 to June 9, indicating the height of the season. 



AMAZILIA SALVINI (Brewster) 



SALVIN'S HUMMINGBIRD 



HABITS 



This seems to be a doubtful species, and evidently is only a hybrid. 

 Only two specimens are known. The type, an adult male, was taken 

 at Nacosari, Sonora, Mexico, by John C. Gaboon, on March 31, 1887, 

 for William Brewster (1893) ; this specimen is now in the collection 

 of the Museum of Comparative Zoology at Gambridge. The other 

 specimen, now in the collection of Dr. Louis B. Bishop (1906), was 

 taken for him by H. W. Marsden at Paymerlee, Gochise Gounty. 

 Ariz., on July 4, 1905 ; this is a young female. 



The best authorities seem to agree that salvini is a hybrid between 

 one of the races of AtnaBilia violiceps and one of the races of 

 Gynanthus latirostris, but which race of each is involved seems open 

 to discussion. Ludlow Griscom (1934) writes: 



A careful study of the color and structural characters of the type convinces 

 me that Cyanomyia salvini Brewster is a hybrid between Amazilia violiceps 

 conjuncta and Cynantlvus latirostris Swainson. These closely related genera dif- 

 fer in (1) Amazilia has the frontal feathering extending forward to and 

 partially concealing the nasal operculum; (2) the tail is slightly forked in 

 Cynanthus, truncate in the section of Amazilia with which we are here 

 concerned. In these respects salvini is an Amazilia as to the frontal feathering, 

 but the tail is slightly forked as in Cynanthus. In size salvini resembles 

 the Cynanthus, a considerably smaller bird than A. violiceps. The color 

 characters combine the two supposed parents perfectly. The glittering violet 

 crown plaque of violiceps combined with the plain green of Cynanthus pro- 

 duces a glittering bluish green plaque. The green upper back fading to 

 dusky green is a perfect combination of the dusky versus dark green upper- 

 parts of the supposed parents. The tail is dark green instead of steel blue 

 versus dull dusky bronzy green, and the feathers have the gray tips of 

 Cynanthus. The underparts are white medially as in the Amazilia, but the 

 sides of the neck and chest are glittering bluish green, passing to green on 

 the sides and flanks, just as in Cynanthus. 



The nest of the hybrid form has, apparently, never been found, but 

 Robert T. Moore has sent me the following note on a nest of Amazilia 

 violiceps ellioH, which very likely is one of the parent forms : 



