Nelson North American Mainland Myiarchus. 25 



both middle and outer pair of feathers and effects a generalized 

 pattern. 



Even the young of M. nigriceps which is without rufous in 

 the adult plumage has it strongly marked on the wings and tail 

 of the young. Among the great number of winter specimens 

 examined I have not found a single individual in this tirst 

 plumage, so it appears that the young moult this plumage within 

 a short time and assume the dress of the adult. 



It is with some hesitation that I add further to the discussion 

 concerning the application of Kaup's Tyrannula mexicana and 

 T. cooperi, a matter which has already been the subject of much 

 difference of opinion; but the case appears to be still unsettled, 

 and my notes may help toward its definite determination. 



In the Proceedings of the Zoological Society of London for 

 1851, p. 51, Kaup described two species of Myiurckus in such 

 a brief and unsatisfactory manner that the application of his 

 names has given rise to much controversy. From recent study 

 of the matter it appears to me that Prof. Baird was right in 

 his disposal of the names (Birds of North America, 1858, p. 

 180) and that their present use by American ornithologists is 

 wrong. The matter cannot be absolutely settled until Kaup's 

 types are examined, but the present evidence in support of 

 Prof. Baird's conclusions are of interest. He recognized 

 Kaup's error in applying Nuttall's Musicapa cooperi (= Tyran 

 nula cooperi Kaup, a synonym of Nuttallornis borealis), to a 

 Myiarchus, and then proceeded to make a new use of the name 

 (loc. cit.), describing in detail as Myiarchus cooperi a specimen 

 from "Mexico" (No. 9100 U. S. National Museum). Baird's 

 type is still in the Museum collection and is the bird from 

 eastern Mexico and the Rio Grande Valley commonly known to 

 ornithologists as Myiorchus mexicanus mexicanus. In case, as 

 I believe, the latter name belongs elsewhere, then Baird's name 

 cooperi becomes available for this species. Baird identified 

 Kaup's Tyrannula mexicana as Lawrence's Tyrannula cineras- 

 cens (Ann. Lye. Nat. Hist. N. Y., V., Sept. 1851, p. 121) and 

 gave it priority over the latter name on the strength of the 

 dates on which the two papers were read; Kaup's paper having 

 been read on February 11, 1851 and Lawrence's in September, 

 1851. According to Sclater (P. Z. S., 1893, p. 439) the part 

 of the Proceedings of the Zoological Society containing Kaup's 



