66^ BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



slightly shorter than outer; hallux (without claw) slig-htly shorter 

 than outer toe (without claw), its claw decidedly shorter than the digit; 

 basal phalanx of middle toe adherent to outer toe for greater part 

 (sometimes nearl}^ all) of its length, to inner toe for about two-thirds 

 of its length. 



Coloration. — Above brown, usually barred or squamated with dusky, 

 the remiges and rectrices uniform dusky; sometimes a white bar across 

 greater wing-coverts; under parts grayish, becoming brown on sides, 

 flanks, and posterior parts, more or less barred or squamated (espe- 

 cially on lateral and posterior portions) with dusk3^ 



Range. — Southern Mexico to Guiana and eastern Ecuador. 



KEY TO THE SPECIES OF MICROCERCULUS.« 



a. Back and scapulars plain brown, without dusky margins to the feathers. (Adults. ) 

 I). Ground color of chest and breast brownish gray or grayish brown, 

 c. Brownish gray of breast, etc., uniform, or with extremely faint brownish 



bars. (Isthmus of Panama.) Microcerculus luscinia, adults (p. 669) 



cc. Brownish gray of breast, etc., not uniform, but varied with dusky or dusky 

 and whitish. 

 d. Brownish gray of breast with V-shaped marks of dusky; flanks darker 

 brown, uniform. (Eastern Costa Rica.) 



Microcerculus daulias, adults (p. 668) 

 dd. Grayish brown of breast with V-shaped and irregular marks of white and 

 dusky; flanks lighter brown, faintly barred with dusky. (Coast of Ven- 

 ezuela. ) Microcerculus pectoralis, adults (extralimital ) ^ 



hh. Ground color of chest and bl-east white (barred with dark grayish brown). 

 (Province of Santa Marta, northeast Colombia.) 



Microcerculus corrasus, adults (extralimital) t' 

 aa. Back and scapulars marked with crescentic bars, or terminal margins, of dusky. 

 (Young.) 

 h. Chin and throat brownish gray, not very different from rest of under parts. 



( Guatemala. ) Microcerculus philomela, young f^ ( p. 667 ) 



hh. Chin and throat dull white, 

 c. Throat spotted with brown; median portion of chest and breast pale buffy 

 grayish, conspicuously marked with spots and crescentic bars of dusky. 



Microcerculus daulias, young (p. 668) 



cc. Throat immaculate dull white; whole chest and breast nearly uniform 



brownish gray Microcerculus luscinia, young (p. 670) 



« Including two allied extralimital species. 



b Microcerculus pectoralis Richmond [in Robinson and Richmond] Proc. U. S. Nat. 

 Mus., xxiv, no. 1247, Oct. 3, 1901, 178 (La Guaira, Venezuela; coll. U. S. Nat. Mus.) 



c Microcerculus 7narginatus {not Heterocnemis marginatus Sclaier) Bangs, Proc. Biol. 

 Soc. Wash., xiii, 1899, 107 (Chirua, Santa Marta, Colombia) ; Allen, Bull. Am. Mus. 

 N. H., xiii, 1900, 180 (Onaca, Santa Marta.) .—Microcerculus corrasus Bangs, Proc. New 

 Engl. Zool. Club, iii, Mar. 31, 1902, 87 (Chirua, Santa Marta, Colombia, 7,000 ft. alt.; 

 coll. E. A. and 0. Bangs). 



This form is closely allied to Microcerculus squanndatus Sclater and Salvin (Proc. 

 Zool. Soc. Lond., 1875, 37, pi. 6), of northwestern Venezuela, and may possibly be 

 the same. 



f'l have not seen the adult of this species, which appears to be undescribed, and 

 hence can not include it in the key. 



