152 Mr. Elliott Coues on the History of 



southward migration, the Island of Cuba would be crossed at the 

 night. 



Geothbjpis macgillim^ayi in summer occupies the Middle and 

 Western states ; and its migration in winter would appear to in- 

 volve no long sea-flight like that of its eastern neighbour. In 

 winter it spreads over Mexico and Guatemala, and thence to Costa 

 Rica, and as far southward as Chiriqui. Here, however, it seems 

 to stop, and does not pass onwards into the southern continent. 

 From this it will be seen that individuals of the two species are 

 found together during the winter months in Costa Rica, but only 

 within the small territory of that republic. On the return of 

 spring the one would prepare for its long flight over the sea, the 

 other to follow the Cordillera northwards, towards their respective 

 summer abodes. 



The migration of G. philadelphia is not without parallel 

 amongst the birds of the Eastern States. The line of migration 

 of Dendrceca castanea is almost identical ; for though its occur- 

 rence has been noted in Guatemala, I never obtained a specimen ; 

 at Panama, hov/ever, it is by no means rare in winter. Dendrceca 

 c(Erulea, too, takes a similar line ; but individuals seem occasion- 

 ally to touch at Cuba, and some (if the specimens cited by Baird 

 have the localities correctly marked) find their way to Guatemala. 



These, and others that might be quoted, seldom touch on the 

 West Indies in their flight, but pass onwards for more southern 

 lands to find their winter homes. 



XIX. Contribution to the History of the Blue Crow of America. 

 By Elliott Coues, M.A., M.D., Ph.D., etc. 



Gymnokitta* cvanocephala. 



Gymnorhinus cyanocephalus, Maxim. Reise, 1841, ii. 21 (French 

 ed. iii. 296; English ed., 287, 297). 



Gymokitta cyanocephala, Bp. Consp. Av. 1850, i. 382; Cass. 

 111. B. Cat. & Tex. 1854, 165, pi. 28; Newberry, Pac. R. R. 



* Gymnorhinus, Maxim., 1841, if sufficiently distinct from Gymnorhina, 

 Gray, 1840 ; if the diiference in termination be not enoiigli, then Cyano- 

 cepliahis, Bp., 1842 ; but if preoccupation in botany precludes, then, failing 

 both these names, Gymnokitta. 



