BIRDS OF NORTH AND MIDDLE AMERICA. 703 



Ch[sctura] semicollaris Hartert, Das Tierreich, Podarg., Caprim., Macropt., 



1897, 74. 

 [Hemiprornr] semicollaris Sclater and Salvin, Nom. Av. Neotr., 1873, 95. — 



Heine and Reichenow, Nom. Mus. Hein. Orn., 1890, 190. 

 Heviiprocnc scmicollai-is Sumichrast, La Naturaleza, v, 1881, 250. 

 Strcptoprocnc semicollaris Oberholser, Proc. Biol. Soc. Wash., xix, May 1, 



1906, 69. 



Genus NEPHGECETES Baird. 



Nephocaetes Baird, Rep. Pacific R. R. Siirv., ix, 1858, 142. (Type, Hinmdo 



nigra Gmelin.) 

 Nephoecetes (emendation) Baird, Rep. Pacific R. R. Surv., ix, 1858, p]). xxix, 922. 

 Nephoecetes (emendation) Sclater, Proc. ZooL Soc. Lond., 1859, 236. 



Medium-sized Chseturine Swifts (length about 135-168 mm.) with 

 tarsus longer than middle toe with claw, hallux more than half as 

 long as inner toe, and tail decidedly to deeply emarginate, with 

 rectrices soft and with normal shafts. 



Nostrils elliptical or narrowly oval, nearly parallel, for tlie greater 

 part posterior to the latero-frontal antia?; distance from tips of 

 longest secondaries to that of longest primary decidedly less than 

 two-thirds the total length of wing; tenth (outermost) primary 

 longest; tail nearly two-fifths as long as wing, decidedly emarginate, 

 the rectrices rather soft, with shafts normal (not rigid, nor mth ex- 

 truded tip); tarsus longer than middle toe with claw; outer toe as 

 long as middle toe, the inner slightly shorter; hallux (without claw) 

 more than half as long as inner toe (without claw); feet relatively 

 rather weak or slender.'^ 



Coloration. — Mostly plam dark sooty, the sides of forehead more 

 or less hoary or whitish; adult females with feathers of posterior 

 under parts more or less distinctly tipped with whitish. 



Nidification. — Nest in recesses among rocks ^ or about buildings, 

 composed of straw, feathers, leaves, bits of paper, etc., loosely put 

 together and not held together by salivary secretion.^ 



Range. — British Columbia and Montana to Costa Rica; West 

 Indies (Cuba, Haiti, Jamaica, Guadeloupe, Martinique, and St. 

 Vincent); British Guiana. (Monotypic.) 



a Nephcecetes differs from all other North American genera of Swifts, at least, in 

 having seven (instead of six) pairs of complete ribs and in having the vomer not 

 expanded distally. (See Lucas, Auk, x, 1893, 365, 366.) 



^ See Vrooman, Condor, vii, 1905, 176, 177, where the eggs are stated to be laid 

 on bare earth behind a tussock of grass, on a shelf or pocket of a cliff overhanging 

 the sea. Doubts have, however, been expressed as to correct identification in this 

 case. That N. niger borealis does nest among rocks, however, I have reason to 

 believe from having seen a large colony at a cliff facing the Carson River near Fort 

 Churchill, Nevada, in June, 1868. (See Orn. 40th Parallel, 1877, 565, 566.) 



c See Gormley, Auk, v, 1888, 424, 425. 



