28 POLIOPTILA C^EBULEA. 



The breeding place of this species was for a long time unknown, but Prof. Baird informs me 

 that Mr. Bannister has recently found a nest in Western New York. It was built in the fork 

 of a tree, some distance from the ground, and contained young. The eggs have never been 

 discovered. I found the birds very abundant at Bethel, Maine, on the 12th of October, 1868, 

 but by the 22d they had all disappeared. They enter Massachusetts in autumn, about the first 

 week of the above named mouth, but have left for the South by the 30th. 



GENUS II. POLIOPTILA. THE WARBLERS. 



GEN. CH. Sternum much narrower and proportionately longer than in the preceding genus ; the marginal indenta- 

 tions are also shallower. The frontal feathers do not cover the nostrils. The tarsi are scutellate. The tail is rounded, 

 whereas in Hegulus it is square and emarginate. 



All the species iu this genus are of small size, with delicate blue colors above and silvery-white below. 



POLIOPTILA C^ERULEA. 

 Silvery Warbler. Blue-gray Gnatcatcher. 



Polioptila ccerulea SCLATEH, Proceedings Zool. Soc. 1855, 11. 



DESCRIPTION. 



Sp. Ch. Form, slender. Size, small. Bill, rather broad at base, acuminate; and with the upper mandible a little 

 curved at the tip, where it is slightly notched. Sternum, rather stoutly built. Tongue, linear, with the end rounded 

 and finely ciliated ; there are also some minute cilia on the sides for one-third of the terminal length. 



COLOR. Adult male. Above, uniform slaty-blue ; brightest on the head, and lightest on the rump, where the 

 concealed portions of the feathers are silky white. Wings above, brown ; with the upper coverts and edges like 

 the back. Tertiaries, margined with white. Tail, black, with three-fourths of the outer feathers, two-thirds of the 

 second, and the tips of the third and sometimes of the fourth, white; with the veins black. Upper tail coverts, 

 black but glossed with the same color as the back. There is also a faint black line over the eye. Beneath, silvery 

 white, with a bluish cast throughout, which is brightest on the sides. Under portions of the wiugs, glaucous with 

 the edges of the feathers and under coverts, white. Under portions of the tail, similar to the back, but with the 

 black more glaucous. Ring around the eye, white. 



Adult female, similar to the male, but with the upper parts paler. The white of the tail is not as much 

 extended. There is no black stripe over the eye. 



Young male, similar to the adult female, but with the under parts paler. 



Young female, with a reddish wash over the upper surface; especially on the head. In all stages of plumage 

 and in both sexes the irides are brown ; bill black with the base of the lower mandible bluish ; the feet and tarsi 

 black. 



OBSERVATIONS. 



After examining a series of twenty specimens, all from Florida, I fail to detect the black frontal line spoken of 

 by Prof. Baird In the "Birds of North America." There is an indication of a black superciliary line but nothing 

 more. 



They are, apparently, intermediate between cterulea and the so-called plumbea; and judging from the description 

 of the latter, I am inclined to doubt its specific claims. This species is distributed, during the breeding season, 

 through Mexico and the Southern and Middle sections of the United States. Winters in the more Southern portions. 



DIMENSIONS. 



Average measurements of forty-eight specimens from Florida. Length, 4-50; stretch, 6-15; wing, 1-95; tail, 

 1-95; bill, -47; tarsus, -07. Longest specimen, 5-00; greatest extent of wiugs, 6-75; longest wing, 2-19; tail, 2-22; 

 bill -56; tarsus, -77; shortest specimen, 4-05; shortest stretch of wing, 5-80 ; shortest wing, 1-75; tail, 1-75; bill, 33; 

 tarsus, -55. 



DESCRIPTION OF NEST AND EGGS. 



Nest. The following is a description of a nest of this species which was kindly loaned me by Mr. L. L. 

 Thaxter, of Newtonville, Mass. It was collected by his son, Roland, on Ladies Island, South Carolina, on May 23, 

 18C9. It is composed of the fine stalks of some delicate plants which are mixed with thistle down and woven together 

 with cobwebs. The whole is formed into a neat structure and smoothly covered with gray lichens, which are also 

 kept in place with the fine silk of the spider-webs, after the manner of the Wood Pewee or the Humming Birds. It 

 is lined with thistle down and lichens. The interior is somewhat purse-shaped, for the mouth is contracted. The 



