1887.] PR()CKKI)1N(;.S OF UNITED STATES NATIONAL MUSEUM. 549 



DESCRIPTION OP THE NEST AND EGGS OF THE CALIFORNIA 

 BLACK-CAPPED GNAT-CATCHER. (POLIOPTILA CALIFORNICA 

 BREWSTER.) 



By CAPT. CHAM. K. BIDiVDIRE, U. S. A. 



This gnat-catcber was iirst described by Mr. William Brewster, from 

 specimeus collected by Mr. F. Stephens near Riverside, San Bernardino 

 County, Cal., March 28, 1878. 



A nest and four eggs of this species have recently been obtained from 

 Mr. Stephens, to whom the credit belongs for the discovery of the first 

 specimens. These were taken near the town of San Bernardino, Cal., on 

 May 2, 3887, and are now in the National Museum collection (Catalogue 

 No. 23294). 



The nest of P. Galifornica, like that of P. plumhea Baird, from Ari- 

 zona Territory, differs radically in structure from that of its eastern 

 relative, P. cccrulea (Linn.), which is too well known to ornithologists to 

 require description. It lacks entirely the artistic finish of the lichen - 

 covered structure of the former, and resembles more in shape certain 

 forms of the nest of the Summer Yellow Warbler, Bendroica cestira 

 (Gml.), and the American Redstart, Setophaga ruticilla (Linn.). 



The nest is cone-shaped, built in the forks of a small shrub, a species 

 of mahogany, Coleogyne ramosessima (Torr.) I think, ow\^ 2 feet from 

 the ground, and it is securely fastened to several of the twigs among 

 which it is placed. Its walls are about half an inch in thickness. The 

 material of which the nest is composed, is well quilted together and 

 makes a compact and solid structure. Externally the nest is composed 

 principally of hemp-like vegetable fiber mixed with small curled-up 

 leaves of the white sage, Eurotia lanata, plant-down, and fragments of 

 spiders' webs. Inside the nest is lined with the same hemp-like fiber, 

 only much finer, and a few feathers. The cavity of the nest is cup- 

 shaped and rather deep. Externally the nest measures 2J inches in 

 diameter by 3^ inches in depth. The inner diameter is Ih inches by If 

 inches in depth. Compared with a ne.st of PoUoptila phimbea Baird, 

 now before me, from Arizona Territory, it seems much better con- 

 structed and also somewhat larger. 



I took three nests of the latter species near Tucson, Ariz., during 

 the months of May and June, 1872. Two of these were placed in bunches 

 of mistletoe, probably Phor edendron flavescens, growing on mesquite 

 trees from 12 to 20 feet from the ground ; and one of them is described 

 in the " History of North American Birds," by Baird, Brewer, and Ridg- 

 way, Volume III, page 502. The third nest was placed in a crotch of 

 a cholla cactus. 



