THE GENUS CHOEDEILES SWAINSON OBEEHOLSEB. 73 



ing, SO that it closely resembles the female of Chordeiles virgvnianus 

 hesperis, as in No. 81569, Amer. Mus. Nat. Hist., Corpus Christi, 

 Texas, May 15, 1882. 



The limited breeding area of this race permits little opportunity 



for geographical variation within its boundaries, and there is none 



'worth mentioning. This bird breeds in Texas from April to July, 



and there are eggs in the United States National Museum collected 



from April 24 to June 28. 



An adult male of this race in the Sennett collection (No. 81591, 

 Amer. Mus. Nat. Hist.), from Wharton County, Texas, taken May 

 27, 1887, was marked by Dr. Elliott Coues as one of the types of his 

 Chordeiles popetue \_=virginiaims] sennefti,^ and upon this basis the 

 range of the latter was extended to Texas. This specimen, as we 

 have already shown,^ can not be considered the type of Chordeiles 

 virginianits sennetti, but must be referred to the present form. 



Regarding the name we are here using for this race the following 

 remarks are necessary : G. K. Cherrie some 18 years ago described ^ 

 a nighthawk from a few specimens from Central America. His 

 type was a specimen taken on the Aserri River, near San Jose, 

 Costa Rica, and he therefore called the supposed new race Chordeiles 

 virginianus aserriensis. I have made every effort to trace this type 

 specimen, but without any success; and Mr. Cherrie himself assures 

 me that he has no idea where it finally went. The application of this 

 name must therefore be settled chiefly by the original description. 

 There is no doubt that Mr. Cherrie had in hand a male nighthawk 

 of the virginianus style in fully grown juvenal or first autumn 

 plumage, not adult, as he supposed. Allowing for this immaturity, 

 the characters that Mr. Cherrie gives are just those distinguishing 

 the small, pale race which summers in southern Texas. A little ad- 

 ditional light is thrown on the subject by a juvenal male nighthawk, 

 No. 128373, U.S.N.M. (still in the National Museum) , collected by 

 Dr. C. W. Richmond on the Escondido River, 50 miles from Blue- 

 fields, Nicaragua, October 28, 1892. This specimen Mr. Cherrie 

 refers to his new race with the remark that it is much darker on the 

 upper surface than his type, as it should be, for it turns out to be 

 really an example of Chordeiles virginianus hesperis! It is, of course, 

 often difficult, owing to the great range of individual variation in all 

 the races of this species, to identify a specimen with absolute cer- 

 tainty from a description alone; but in this case, in view of the 

 ra,ther full description which agrees in all respects with the characters 

 of the present form, it seems best to use for this race the title 



'■ Auk, vol. 5, January, 1888, p. 37. 



''Pages 55-56. 



sAuk, vol. 13, April, 1896, p. 136. 



13732°— Bull. 86—14 6 



