^°^i^T^^n Clark, Pterylosis of Podargus and theCaprimulgi. i6q 



Caprimulgi. There are ten longitudinal rows on the crown and 

 their arrangement is somewhat as in Nyctidro7mis. The pterylosis 

 of the head, however, differs from that of all other North American 

 genera in the much greater density of feathering on the front and 

 sides of the forehead, and on the back of the crown. The median 

 band on the front of the crown is also broader and denser than in 

 the smaller Caprimulgi. The row of pinnate rictal bristles is very 

 prominent. The upper cervical tract forks very widely : the 

 branches are narrow and are indistinctly connected with the ends 

 of the humeral tracts. The dorsal tract is deeply forked anteriorly 

 and well-defined. It is also forked at the base of the oil-gland, 

 so that there is a distinct apterium there, as in some of the owls. 

 The femoral tracts are rather large but are entirely confined to the 

 femurs. The ventral tracts are broad on the breast and narrow 

 gradually on the belly, each longitudinal row being successively 

 shorter, beginning with the innermost. The ' hook ' connecting this 

 tract with the hypopterum is very prominent. The feathering of the 

 infra-mandibular region is very sparse, consisting of 9 longitudi- 

 nal rows. The tarsus is feathered nearly to the toes in front. 

 Aftershafts are large, the oil-gland is bare, the filoplumes are long 

 and down feathers are wanting. There are 10 rectrices, of which 

 the middle pair are longest. There are 10 primaries (8, 7, 9, 6, 

 5, 4, 3, 10, 2, i), 14 secondaries and 3 feathers in the alula. 

 The wing is aquincubital. Judged from the pterylosis alone, there 

 is no justification for uniting the Chuck-wills-widow and the Whip- 

 poorwill in the same genus, for they differ quite as markedly as 

 any other two American genera. We may therefore refer the 

 former to Afitrostomus and the latter to Caprimulgus, though it 

 may be the European species of Caprhmdgus do not agree with 

 it in detail. It is impossible to determine from Nitzsch's figure. 



Podargtis and Antrostomus are much larger than any of the 

 American genera which have been examined hitherto and several 

 of their peculiarities (as for example the large number of second- 

 aries) are doubtless due to their greater size. But in most, if not 

 all of the points in which they differ from other Caprimulgi, they 

 seem to approach the owls, and thus confirm the opinion which I 

 expressed in 1894 (Proc. U. S. Nat. Mus., Vol. XVII, p. 572) 

 that, judged by their pterylography, "the Caprimulgi are related 



