290 General Notes. [ A ^ 



months and the species did not occur again until December 8 when one 

 was observed skulking in a brush pile below the cabin. One bird (presum- 

 ably the same one) is still present on the island at present writing (January 

 12, 1919). 



The instances given here are indications of the conditions limiting the 

 range of the Carolina Wren, in one direction at least and show, too, how 

 readily a species apparently common may be reduced or even exterminated 

 in a given region in a very short period of time. In the case of the Carolina 

 Wren the heavy blanket of snow covering the food supply would seem to be 

 the direct cause of extermination rather than prolonged cold, as here at 

 Washington these birds were able to survive a low temperature for a con- 

 siderable period but were killed when deep snow covered the greater part 

 of their normal feeding ground. It is to the comparatively few that are 

 able to survive that we must look for the perpetuation of the species. 

 The increase in numbers however, seems to be a slow process, as following 

 their decrease in 1912, I found the species still comparatively rare near 

 Lawrence, Kansas, in 1914, 1916 and as late as November, 1918. — 

 Alexander Wetmore, Biological Survey, Washington, D. C. 



The Affinities of Chamsethlypis. — As generic distinctions become 

 more and more refined the need of a supergeneric group intermediate 

 between the family or subfamily and the genus, corresponding approxi- 

 mately to the former genus, becomes increasingly evident. 



In his great work on the ' Birds of North and Middle America ' Mr. 

 Ridgway has supplied this want in many families. In the Warblers (Mnio- 

 tiltidae) the grouping does not appear to be so successful as in most cases. 

 Not only is the old genus Geothlypis broken up into three genera but these 

 are distributed in as many supergeneric groups. Oporornis is banded with 

 Dendroica and its allies in the Dendroicse, while Chaina'thlypis is placed 

 in the Icterise. 



We cannot help feeling that this arrangement is artificial, and that 

 too much importance has been placed on the length of the wing-tip (easily 

 modified by habits and migration), and insufficient weight given to colora- 

 tion, nesting and even song. 



Also, the distinctions are partially invalidated by exceptions. Thus 

 the sections including Geothlypis and Cham&thlypis are separated by differ- 

 ences in the length of the tail and form of the bill; but Geothlypis nelsoni 

 agrees with Chamaelhlypis in having the tail longer than the wing. Again 

 the Geothlypese are separated from the Dendroiceae by having the rictal 

 bristles obsolete and the wing-tip shorter, but in Geothlypis cequinoctialis 

 and G. cucullata, at least, the rictal bristles are well-developed. 



The particular point of criticism is in regard to the affinities of Chamce- 

 thlypis which is distinguished from Geothlypis by its stouter bill, with 

 strongly curved culmen, and its longer, graduated tail. 



Mr. Ridgway expresses the opinion that while " this genus is very much 

 like Geothlypis as to its general appearance " it is " quite distinct struc- 



