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



In examining an extensive series of specimens I find some differences which may he of 

 importance. Thus, in the Columhia river specimens the entire hack and scapulars are nearly 

 pure uniform green, with the faintest possible wash of purplish brown. The feathers on the 

 rump are purplish violet, slightly glossed with green. In 6625, from the Copper mines, the 

 back is purplish brown, with only a trace of green ; the rump nearly pure bluish green, with 

 the merest trace of violet. In a specimen from Agua Nueva the colors are much as in the last, 

 except thafthe purplish brown is more confined to the scapulars and the middle of the back, as 

 in the Columbia river specimens. The wing is longer than in any I have seen, (4f inches.) 



In one specimen from Tejon Pass, apparently immature, the tertials are terminated broadly 

 with pure white. 



The female differs in the much less brilliancy of color, especially that on top of head and 

 rump, the former more brown. The under parts are dirty white. 



List of specimens. 



COTYLB, Boi 



CotyU, BoiE, Isis, 1822, 550. (Type H. rifaria.) 

 Ch. — Bill very flat, extremely broad at the base, and gradually narrowed towards the tip ; nostrils prominent and rounded. 

 Tail moderate, nearly straight or somewhat emarginated. Tarsi rather shorter than the middle toe, slender and scutellated. 

 Toes very slender, the claws slightly curved. Colors generally dull brown above, without gloss. 



This genus is distinguished from Hirundo by the slightly forked tail, rather long tarsi, very 

 slender toes, and extremely dull colors. The two United States species are the smallest we 

 have. Each will form the type of a special division, of at least sub-generic value, with the 

 following characters : 



Cottle, Boie. — Tarsi with a tuft of feathers near the toes, on the posterior face. Edges of 

 outer primaries normal. 



Above grayish brown ; beneath white, with a well defined pectoral band C. riparia. 



Stelgidoptbryx, Baird. — Tarsi naked. Edge of outer primary with the fibrillae converted 

 into a series of stiffened recurved hooksi. 



Above light sooty brown ; the under parts brownish ash, fading behind into white. 



8. Berripenim. 



