NORTH AMERICAN BIRDS. 229 



ianus. Their sizes are i.i2x .81, 1.06 x. 80. The average size, accord- 

 ing to Prof. Ridgway, is 1.13X.80. 



421. Chordeiles texensis Lawr. [358.] 



Texan Nighthawk. 



Hab. Southwestern border of the United States — Texas to Southern California, south to Costa Rica. 



The Texan Nighthawk is smaller than the foregoing species, the 

 general tone of the plumage lighter, and it differs otherwise. It is a 

 common species in various regions in Southern Texas, New Mexico, 

 Arizona, etc. Mr. Sennett describes its flight as resembling that of 

 the Whip-poor-will, but it does not indulge in the perpendicular de- 

 scents accompanied by the whir of wings so characteristic of C. vir- 

 ginianus. On the Lower Rio Grande eggs were obtained as early as 

 April 26, and fresh ones found as late as May 19. They were always 

 laid on the bare, hot ground. Dr. Merrill states that the notes of this 

 species are a curious mewing call difficult to describe. He found the 

 eggs in the vicinity of Brownsville, Texas, usually deposited in ex- 

 posed situations, among sparse chaparral on ground baked almost as 

 hard as a brick by the intense heat of the sun. One set was found on 

 a small piece of tin, near a frequented path. Mr. Rachford informs 

 me that in Jefferson county, Texas, this species usually deposits its 

 two eggs on the ground, in a well-beaten cow-path ; the nesting season 

 begins from about May loth, and eggs may be found in the latter 

 part of June. Dr. Merrill states that the eggs vary considerably, but 

 exactly resemble the surface on which they are placed. The ground- 

 color is usually clay ; some are very sparingly dotted with brown ; 

 others mottled with light brown and obscure lilac ; some are so thickly 

 marbled with brown and lilac on a dark ground as to give them a 

 granite-like appearance. They average 1.07 x .77. 



422. Cypseloldes niger (Gmel.) [350.] 



Slack Swift. 



Hab. Western portions of the United States, north tcs Colorado, Nevada, Oregon, Washington Terri- 

 tory and British Columbia; south to Southern Central America; Jamaica, Hayti and other West India 

 Islands. 



The Black Swift has been met with sparingly in the various regions 

 cited in the above habitat. Another common name for this bird is 

 Northern Black Cloud Swift. Comparatively little has been ascer- 

 tained concerning its general habits, and its eggs have remained un- 

 known until the present year (1888), when Mr. M. H. Gormley discovered 

 its nest and eggs in the town of Seattle, King county, Washington Terri- 

 tory. June 6 he found a nest in the interior of a cornice of a small 

 frame building situated on Yesler's Wharf of that city. The entrance 

 to the nest was at one end of the cornice ; the deck or top being sprung 



