246 



U. S. p. R. E. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



OPORORNIS/ Baird. 



Ch. — Bill sylvicoline, rather compressed ; distinctly notched at tip; rictal bristles very much reduced. Wings elongated, 

 pointed, much longer than the tail ; the first quill nearly or quite the longest. Tail very slightly rounded ; tail feathers 

 acuminate, pointed ; the under coverts reaching to within less than half an inch of their tip. Tarsi elongated, longer than 

 the head ; claws large, the hinder one as long as its digit, and longer than the lateral toes. Above olive green ; beneath 

 yellow ; tail and wings immaculate. Legs yellow. 



This group of American warblers is very distinct from any other. The typical species is 

 quite similar in color to Geothlypis Philadelphia, but is at once to be distinguished by much 

 longer wings, more even tail, and larger toes and claws. It is also very similar to Seiurus, 

 differing chiefly in the longer wings, larger claws, and absence of spots beneath. 



Throat and crown ash color ; a white ring round the eye. No black on the side of 



the head 0. agilis. 



Throat and superciliary stripe yellow ; top of the head and a streak beneath the eye 

 black O.formosas. 



Comparative measurements of species. 



OPOEOKNIS AGILIS, Baird. 



Connecticut Warbler. 



Sylvia agilis, Wilson, Am. Orn. V, 1812, 64 ; pi. xxxix, f. 4. — Bonap. Obs. Wils. 1825, no. 163. — AvD. Orn. Biog. 



11,1834,227; pi. 138. 

 Sylvicola agilis, Jardine ed. Wilson, 1832. — Rich. List, 1837. — ^AuD. Synopsis, 1839, 63. — Is. Orn. Biog. II, 1841, 



71 ; pi. 99. 

 Trichas agilis, Niittall, Man. I, 2d ed. 1840, 403. 

 Trichas tephrocotis, Ndttall, Man. I, 2d ed. 1840, 462, (Chester county, Penn., adult with whole head ash.) 



Sr. Ch. — Upper parts and sides of the body uniform olive green, very slightly tinged with ash on the crown. Sides of the 

 head ash tinged with dusky beneath the eye. (Entire head sometimes ash.) Chin and throat grayish ash, gradually becoming 

 darker to the upper part of the breast, where it becomes tinged with dark ash. Sides of the neck, breast, and body, olive, like 

 the back ; rest of under parts light yellow. A broad continuous white ring round the eye. Wings and tail feathers olive, 

 (especially the latter,) without any trace of bars or spots. Bill brown above. Feet yellow. Length , 6 inches ; wing, 3 ; 

 tail, 2.25. 



Hail.— Eastern United States. (Very rarely seen.) 



In this species the wings are long and pointed, reaching beyond the middle of the tail or 

 within an inch of the end, (in the fresh specimen.) The primaries are .85 of an inch longer 

 than the secondaries. The primaries become successively and decidedly shorter than the first, 

 which is longest. The tail feathers, are broad, acuminate, and slightly graduated. 



A second specimen (2939) is similar, but differs in having the crown dark plumbeous ash. 

 Both of these are spring specimens. In fall, when the species is much more frequently seen, 



' Tlio name is used in reference to the abundance of 0. agilis in autumn, compared with its excessive rarity in spring. 



