BIRDS OF NORTH AND MIDDLE AMERICA, 703 
Ch[ztura] semicollaris Hartert, Das Tierreich, Podarg., Caprim., Macropt., 
1897, 74. 
[Hemiprocne] semicollaris ScuarER and Satvin, Nom. Av. Neotr., 1873, 95.— 
Heme and Rercnenow, Nom. Mus. Hein. Orn., 1890, 190. 
Hemiprocne semicollaris SumicHrast, La Naturaleza, v, 1881, 250. 
Streptoprocne semicollaris OBERHOLSER, Proc. Biol. Soc. Wash., xix, May 1, 
1906, 69. 
Genus NEPHCCETES Baird. 
Nephocaetes Barrp, Rep. Pacific R. R. Surv., ix, 1858, 142. (Type, Hirundo 
nigra Gmelin.) 
Nephoecetes (emendation) Barrp, Rep. Pacific R. R. Surv., ix, 1858, pp. xxix, 922. 
Nephecetes (emendation) ScuatEeR, Proc. Zool. Soc. Lond., 1859, 236. 
Medium-sized Cheturine 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 the greater 
part posterior to the latero-frontal anti; 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 with 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 plain 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.) 
« Nephecetes 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.) 
b 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.) 
¢ See Gormley, Auk, v, 1888, 424, 425. 
fa 
