NATURAL SCIENCES OP PHILADELPHIA. 71 



trifle longer, the latter exceeding the former, on an average, .10 

 to .25, instead of equalling the wings. 



Yar. " pertinax" not distinguishable even as a local race ; the 

 specimens vary inter se, and some of them are perfect duplicates 

 of my Arizona skins. The yellow-bellied Tehuantepec bird comes 

 much nearer the requirements of a geographical variety. 



Baird's erroneous identification of Kaup's " mexicana" is per- 

 fectly excusable, and, indeed, was well nigh unavoidable under the 

 circumstances. Kaup's careless notice is worthless for all practi- 

 cal purposes, and we have to thank Dr. Sclater for telling us 

 what his bird really is. (Cf. Lawr., P. A. N. S. P., 1871, 235.) 

 Other American writers copied Baird's mistake. This point 

 settled, the sjmonymy of the bird is plain, Mr. Lawrence's origi- 

 nal description being perfectly satisfactoiy. 



Specimens examined, thirt} r -five, from the above-mentioned and 

 intermediate localities. 



4. Myiarchus tyrannulus. 



Muscicapa tyrannulus, Mull. (G. R. Gr., H.-L. No. 5527.) 



Muscicapa aurora, Bodd., P. E. 571, f. 1. (G. R. Gr.) 



Muscicapa flaviventris, Steph. (G. R. Gr.) 



Muscicapa ferox, Gm., S. N. i. 934, e Buff. 1. c. Max. Beitr. iii. 285. 



Tyrannus ferox, Vieill., Erie. Met. ii. 848; Sws., Quart. J. xx. 1826, 



276; D'Orb., Voy. Ois. 306. 

 Myiarchus ferox, Cab., Orn. Not. i. 248; Schomb. Guiana, iii. 700; 



M. H. ii. 73 ; Burm., Syst. Uebers. ii. 470; Scl. P. Z. S. 1855, 150 ; 



C. A. B. 233. 

 Myiarchus sioainsoni, Cab., M. H. ii. 72. (Specim. Braziliana.) 

 ' Myiarchus panamensis, Lawr., A. L. N. Y vii. 1860, 284, 295. (Spec. 



e i anama et N. Grenada). Id., ibid. ix. 1868, 115. (Costa Rica.) 

 Myiarchus venezuelensis, Lawr., P. A. N. S. P., 1865, 38. (Sp. junior. 



e Venez.) 



M. inter majores, rostro modico ; olivaceo-fuscus, gula, cinerea, 

 ventre flavo, alis caudaque fuscis, baud rufo indutis, rectricibus 

 concoloribus, remigibus primariis intus, secondariis ex intus et 

 extus, flavido marginatis. Long tot. 7-7.75 ; alee 3.30-3.70, caudge 

 3.50-3.90, tarsi .80-.90, rostri .65-.75. 



Habitat Amer. Cent, et Merid. Panama (Hicks, McLeannan, 



Galbraith, Mus. G. N. L.). Venezuela (Nash, Mus. G. N. L.). New 

 Granada (Schott, Mus. S. I.). Costa Rica (Arce, Mus. O. S., fide 

 Lawr. 1. c). Para, Bogota, Trinidad, Tobago, Bolivia (Mus. P. L.S.. 



1872.] 



