>SS7-] Correspondence. 26c 



Anthus spragueii. Four seen. 



Thryothorus ludovicianus. One seen. 



Thryothorus bewickii. One seen. 



Turdus fuscescens. One seen. 



Turdus aonalaschkae pallasi. Not common. 



This is a prairie country and many of the birds named in Mr. Drew's list 

 are not found here. — P. M. Tiiorne, Capt. 22d Inft'y, U. S. A., Fort 

 Lyon, Col. 



CORRESPONDENCE. 



[Correspondents are requested to write briefly and to the point. No attention ivill 

 be paid to anonymous co»i»iu>iications.~\ 



Individual Variation in the Skeletons of Birds, and other matters. 



To the Editors of The Auk: — 



Dear Sirs: — -Before saying anything about the individual variation in 

 the skeletons of birds, allow me to pass a few remarks upon the letters of 

 Dr. Stejneger and Mr. Lucas, which appeared in the last issue of 'The 

 Auk' (April, 1SS7), and wherein I am called upon to hold up my hands 

 for a number of sins. Dr. Stejneger is quite correct in calling me to ac- 

 count for saying that 'such forms as Pi'cus' were birds with a 'two-notched' 

 sternum; all Woodpeckers have four notches in their sternums, as we well 

 know, and I must be pardoned for making such a lafsus calami or lapsus 

 memories, whichever it was. When Dr. Stejneger asks the question, how- 

 ever, with respect to the Swifts and Hummingbirds, and says, "What in 

 the nature of these birds' flight has brought about such an extraordinary 

 similarity, osteologically, myologically, and pterylographically in the 

 wing-structure of the Swifts and Hummingbirds, as compared with that of 

 the Swallows?" — it's another matter. And so far as the osteology of the 

 wing-structure of a Swift and a Hummingbird is concerned and their "ex- 

 traordinary similarity," I would simply invite Dr. Stejneger's attention to 

 a short paper of mine in a recent issue (the April number, 1SS7, Ibelicve) 

 of the 'Proceedings' of the Zoological Society of London, wherein I have 

 figured the humerus for a Swallow, Swift and a Hummingbird, and ask 

 him where the "extraordinary similarity" comes in, in that part of the 

 wing-structure of the last two forms mentioned? 



As to the other extraordinary similarities I will dwell upon them in 

 another connection, later. 



Mr. Lucas's letter requires no special notice, for I must still plead not 

 guilty to the charge of having published an "imperfect" drawing of the 

 base of the skull of Tachycincta thalassina, and that is the sole point of 



