NATURAL SCIENCES OP PHILADELPHIA. v 15 



that it is even a recognizable variety. It is true that in Costarica 

 laivrencii tends to be a little darker on the pileum, with the yellow 

 a little more extensive ; but it is also true that these characters 

 will not decide the status of ten per cent, of current specimens. 

 NigHcapillus is simply a slight tendency towards nigriceps. 



The normal variations in size and color are precisely parallel 

 with those already discussed under head of M. cinerascens. 

 Northern and western specimens average a trifle paler than 

 usual ; the southernmost are the brightest. Sometimes the 

 edgings of the inner remiges and the coverts are whitish. Tehu- 

 antepec skins show the stoutest bill ; this is likewise the case in 

 crinitus var. and cinerascens, showing the uniform operation of 

 some unknown local influences. One example (34,810, Mus. S. I., 

 Costarica) has exceptionally short wings and tail, these members 

 measuring only 2.80 and 2.90 respectively. 



Specimens examined, thirty-three. The bird seems to range 

 throughout Mexico and Central America. I have never seen a 

 United States skin, and though the species may overstep the 

 Mexican boundary, this remains to be shown. Probably Giraud's 

 bird came from Northeastern Mexico, as some others of his sixteen 

 "Texas" birds certainly did. 



7. Myiarchus nigriceps. 



Myiarchus nigriceps, Scl., P. Z. S. 1860, 68, 295; Cat. A. B. 234 



(Ecuador). Lawr. Ann. Lye. 1861, 327 (New Grenada). 

 Myiarchus hrunneiceps, Lawr., 1. c. (nomen pro temp.). 



M. inter minores, rostro lato depresso ; clare olivaceus, pileo 

 statim nig-icante, gula restricta clare cinerea, pectore et ventre 

 flavissimis ; alis caudaque fusco-nigris, hac innotatis, illis minime 

 rufalbida marginatis. Long. tot. 5.60-6. 25 ; alis et cauclae 2.90-3.10, 

 rostri .60-.65, tarsi .65-. 70, rostri lat. ad basin .30. 



Habitat. Ecuador (Pallatanga, Esmeraldas, Fraser, fide Scl., 

 1. c; Quito, Backalew, Mus. S. I.). Panama (McLeannan and 

 Galbraith, Lawr., 1. a). Mus. Gr. N. L. and S*. I. 



Obs. Distinguishable on sight from lawrencii by the black or 

 blackish cap, in marked contrast with the clear olive back, exten- 

 sion of the rich yellow high up the breast, and particularly by the 

 absence of. rufous on the tail ; in this respect comparing with 

 lawrencii just as ferox does with crinitus. The wings, as usual 

 in the genus, share the extinction of rufous on the tail ; a mere 

 rufous trace can only be detected in some specimens on the outer 

 1872.] 



