NATURAL SCIENCES OF PHILADELPHIA. 67 



Tims we arrive at the above synonym}'. I should add. in 

 justice to an excellent young ornithologist, noted for discrimi- 

 native abilities, that I am not the first to perceive the identity of 

 the specimens here discussed. They are all labelled "mexicanus" 

 in Robert Ridgway's handwriting he having accurately distin- 

 guished them from the following larger, heavier-billed form from 

 Southern Mexico. But Kaup's name, even if it belongs here, is 

 clearly anticipated by Vieillot's. 



Specimens examined, ten. 



c. vae. cooperi. 



" Tyrannula mexicana, Kanp, P. Z. S., 1851, 51," auctoritate Sclat- 

 eriana, fide Lawr., P. A. N. S. P. 1871, 235. Non auctorum! 



Tyrannula cooperi, Kanp, P. Z. S. 1851, 51. Non Muscicapa cooperi 

 Nuttall, quae Contopus borealis. 



Myiarchus cooperi, Baird, B. N. A. 180. Scl. P. Z. S. 1859, 384; C. A. B. 

 233. S. and S., Ibis, 1859, 122, 440. 



M. Myiarcho crinito similis ; maxim us inter majores; rostro 

 enormi, nigro; notreo obscuriore, gastrseo dilutiore; fusco et rufo 

 in pogoniis interioribus rectricum fere dimidiatis. Long, rostri a 

 fronte in apicem .80-1.00; aire et caudoe 3.90-4.25; tarsi .S5-.95 ; 

 long tot. (exuviarum) 7.50-9.00. 



Habitat. Mexico, prresertim partibus merid.-occid. "Mexico" 

 (Verreaux, Salle, Mus. S. I.). Tehuantepec (Sumichrast, Mus. S. 

 I. et G. N. L.). Mazatlan, Guadalaxara (Grayson, Mus. S. I.) 

 "Gautemala" (Mus. P. L. S., fide ejusd. Cat.). 



Obs. This variety is distinguished, in its extreme of develop- 

 ment, from crinitus by the larger size, skins running up to nine 

 inches; by the larger bill, which sometimes attains a length of an 

 inch, and equals, or even slightly exceeds, the tarsi, which are 

 themselves usually a tenth of an inch longer than in crinitus; 

 by the olivaceous being not so clear as in crinitus, nor the under 

 parts (usually) so bright yellow; and especialty by the presence 

 of a band of fuscous on the inner webs of the rectrices, varying 

 from i or ^ to nearly ^ the width of the vanes. In its strongest 

 differentiation, the variety looks very different from t3^pical crini- 

 tus, but with only a dozen specimens on hand, I can trace it 

 directly into crinitus, of which it is unquestionably a mere local 

 race. It seems nearly confined to southern and southwestern 

 Mexico; Sclater, however, quotes it from Guatemala. 



1872.] 



