Correspondence. [April 



CORRESPONDENCE. 



\Correspondeiits are requested to write briefly and to the point. No attention will 

 be paid to anonymous com7nunications.~\ 



Observations on the Pterylosis of Certain Picidae. 



To THE Editors of The Auk : — 



Dear Sirs: — On the 25th of last August, 'Forest and Stream' very kindly 

 published a contribution of mine entitled 'A Chapter on Pterylography,' 

 which was illustrated by live figures. That paper pretended to be nothing 

 more than a good guide to those interested in pterylography, and who 

 desired to know something of one of the best characters we find in birds to 

 assist us in their classification. It was also written with the hope that 

 those who had the opportunity might more carefully examine into this 

 character among our own birds, and in time be enabled to make some 

 useful contributions to the subject. 



In the 'Chapter' I refer to, my chief examples were chosen from the 

 Woodpeckers, and in the course of my demonstrations of the apteria and 

 pterylcB, as found among certain forms of those birds, a number of inter- 

 esting and important facts came to light. Since then, I have carefully 

 examined the pterj'losis in the genus Colaftes., and compared it with addi- 

 tional specimens of Dryobates and Sphyrapicus. Had I been ready to 

 pluck certain tempting specimens from the Pacific coast region, which I 

 have by me in alcohol, and for which I am under great obligations to Mr. 

 G. Frean Morcom of Chicago, and Mr. F. Stephens of San Diego, Cal., 

 I might have thrown perhaps still more light upon this subject, but these 

 specimens I am reserving for a future and more extended memoir upon 

 the Pici. At any rate I would like to review in the present connection 

 some of my observations upon the pterylosis of the American Picidre, and 

 bring the facts in question more directly to the notice of working ornith- 

 ologists. 



Nitzsch in his classical volume on 'Pterylography' (English Trans.) 

 confesses to have been able to examine only a few species of Wood- 

 peckers, so his account of the pterylosis in this group of birds is not as 

 full as it might otherwise have been. His investigations were apparently 

 confined to Picas luridus (a species of Sumatran Woodpecker, first 

 described by him, and which lacked the small "inner humeral tract"), P. 

 tridactylus, P. carolitttis, P. beuffalensis, P. auratw^, P. medius, P. 

 macei, P. martins, together with Picumtius 7ni?iutus, and Yunx torquilla. 



In his descriptions of the pterylosis in Pici, this eminent observer calls 

 attention to the submedian, longitudinal capital apterium, extending 

 along the elevation caused by the underlying limbs of the prolonged 

 hyoidean apparatus. This is shown at b, c, in Fig. 2 of the present 

 letter. 



