BIRDS OF NORTH AND MIDDLE AMERICA. 407 



somewhat aberrant in having the tail very nearly as long as the 

 wing, the middle toe longer, compared with the tarsus, and the bill 

 slightly more depressed, the differences are by no means sufficient to 

 warrant placing it in a different genus. Whether it is really a Pogo- 

 notriccus"' or not I am not able to determine, no species of that sup- 

 posed genus being at present available for comparison; but if it should 

 prove to be congeneric with the type of the latter then Pogonotriccus 

 should be considered a synonym of Tyranniscus. 



KEY TO THE SPECIES AND SUBSPECIES OF TYRANNISCUS. 



a. Under parts with yellow or yellowish only on sides and flanks. 



h. 8upraloral region and upper eyelid grayish white; pileum dull slate color or gray- 

 ish dusky, different from olive-green of hack. ( Tyranniscus rilissimiis.) 

 c. Larger (wing of male 58-60, averaging 59.3, of female 52); sides more strongly 

 olive-yellow. (Guatemala and Honduras. ) 



Tyranniscus vilissimus vilissimus (p. 408). 

 cc. Smaller (wing of male 47-56.5, averaging 51, of female 41-50, averaging 46.2); 

 sides less strongly olive-yellowish'. (Nicaragua to Panama.) 



Tyranniscus vilissimus parvus (p. 408). 

 bb. Supraloral region and upper eyelid yellow; pileum greenish olive, like l)ack. 



(Colombia to Peru and Venezuela.) Tjn-anniscus chrysops (extralimital) b 



aa. Under parts wholly yellow and olive except chin and upper throat. 



b. Tail not longer than distance from bend of wing to end of secondaries; pileum 



sooty black. (Colombia to Peru.) Tyranniscus nigricapillus f extralimital) <^ 



bb. Tail nearly as long as distance from bend of wing t< ) tip of h ingest primary; pileum 

 slate-gray. (Colombia.) Tyranniscus plumbeiceps (extralimital) d 



a Pogonotriccus Cabanis and Heine, Mus. Hein., ii, 1859, 54. (Type, Muscicapa 

 eximid Temminck). — Eupsilostoma Sclater, Proc. Zool. Soc. Lond., 1860, 68. (Same 

 type.) 



b Tyrannulus chrysops Sclater, Proc. Zool. Soc. Lond., 1858 (pub. 1859), 458 (Guala- 

 fjuiza, Ecuador; coll. P. L. Sclater). — Tyranniscus chrysops Sclater, Cat. Am. Birds, 

 1862, 216; Cat. Birds Brit. Mus., xiv, 1888, Ub.—[Elainia] chrysops Gray, Hand-list, i, 

 1869, 356, no. 5413. — T[yranniscus] flarifrons Cabanis and Heine, Mus. Hein., ii, 1859, 

 58, footnote ("New Granada"; coll. Berlin Mus.). — Tyrannulus JJavidifrons Sclater, 

 Proc. Zool. Soc. Lond., 1860, 69 (Pallatanga, e. Ecuador; coll. P. L. Sclater). — 7yan- 

 niscus flavidifrons Sclater, Cat. Am. Birds, 1862, 216. — {Elaiuin] Jhtridifnrns <^iray. 

 Hand-list, i, 1869, 356, no. 5412. 



It is possible this species, as generally understood, may require sulxlivision, Itut I 

 liave neither the material nor time for inquiry into the matter. 



<" T[yrannulus] nigro-capillus Lafresnaye, Rev. Zool., Sept., 1845, 341 (Bogota, 

 Co]oml)ia)\ — Tyrannulus nigricajnll us Sclater, Proc. Zool. Soc. Lond., I860, 93 (above 

 Puellaro, Ecuador; crit.). — T[yranniscus] nigricapillus Cabanis and Heine, Mus. Hein., 

 ii, 1859, 57. — Tyranniscus nigrica pill us Sclater, Cat. Birds Brit. Mus., xiv, 1888, 131. — 

 [Elainia] nigricapilla Gray, Hand-list, i, 1869, 356, no. 5416. 



(1 See footnote b on p. 406. 



