340 



DE. R. W. SHFEELDT's MOEPHOLOaiCAL 



Commencing with the pterylosis of the head, I find in A. voci- 

 ferus the same character which Nitzsch points out for the 

 European Whip-poor-will (see PI. XVIII. figs. 9 and 10 of this 

 paper), and tliat is, on its superior aspect there is a triangular 

 patch filliDg in the space just posterior to the superior mandible. 

 Behind this the feathers form a median longitudinal tract of 

 some width, which, extending down the back of the neck, as the 

 dorso-cervical tract, forks between the shoulder-blades. Between 

 this median tract on the top of the head and within the superior 

 eyelid, on either side, we find a double longitudinal tract of 

 contour feathers which join those in front, and posteriorly unite 

 with the pterylosis of the inferior aspect of the head or the 

 throat. Apteria occupy the interspaces among these supra- 

 capital, longitudinal pterylae on the head of this "Whip-poor-will, 

 and as a distinctive feature it is even better marked in our speci- 

 men of Chordeiles. 



It will be remembered that Nitzsch figured this character for 

 Gaj^rimulgus europceus and Nyctornis grandis, while he states in 

 the text that he compared these two forms with C. longipennis, 

 C. forcipatus, and C. psalurus. He also examined pterygraphi- 

 cally ^gotheles Novcc-Hollandice, Podargus gigcts, and Nyctornis 

 (sthereus. 



On the throat of the Common American Whip-poor-will the 

 feathers are arranged in fairly well-defined, longitudinal rows, 

 and Nitzsch found this to be characteristic also of the European 

 bird ; but in Chordeiles these rows are not very easily made out, 

 if the throat-feathers are inserted upon any definite arrangement, 

 and I am inclined to believe that in this latter form this is not 

 the case. 



Anteriorly the cervical region is densely feathered in both 

 Antrostomus and CJiordeiles, the tract extending to the points 

 opposite the clavicular heads of the os furcula, laterally ; while 

 mesially an aptera occurs of no great extent between the forks 

 of the bone just alluded to (fig. 9). 



Nitzsch found a different state of things in this region in the 

 European Nightjar, for he draws the entire antero-cervical space 

 without feathers, which reduces the neck-tracts to two longi- 

 tudinal, lateral pterylse*, as shown in his figure of that bird. 



The superior mandibular bristles in the Whip-poor-will before 

 me are conspicuously long, and are deeply inserted as a single 

 * " Feather-tracts," from nTepov and vXij. 



