76 TTEANNID^. 



p. 308 ' J Salv- P. Z. S. 1870, p, 199 ' ; Baird, Brew., & Ridgw. N. Am. B. ii. p. 363 ' ; Ridgw. 



Ibis, 1886, p. 467°; Scl. Cat, Birds Brit. Mus. xiv. p. 231 '. 

 Empidonax viridescens, Ridgw. Pr. U. S. Nat. Mus. vi. p. 413 ^ 

 Quam prsecedentes pectore multo magis ochraceo. 



Eab. Costa Eica, Barranca ^ 2, Dota Mountains, Grecia^ (Carmiol), Quebrada Honda 

 {v. Frantzius 2), Irazu {H. Rogers) ; Paxama, Volcan de Chiriqui^, Calovevora^ {Arce). 



This species seems fairly separable from the more northern E. salvini and E. bairdi^ 

 the most obvious character being the ochraceous tint on the chest. In some specimens 

 the head and back are of a browner olive, but this is an evanescent character. Upon 

 the specimens with the more olivaceous upper plumage Mr. Ridgway founded his 

 E. viridescens, but with a typical specimen oi E. Jiavescens before us, and others com- 

 pared with the type of E. viridescens, we do not see how two Costa-Rican species can be 

 established — some allowance must be made for age, season, &c. 



b. Eostrum angustulum. 



10. Empidonax hammondl. 



Tyrannula hammondi, Xantus de Vesey, Pr. Ac. Phil, 1858, p, 117', 



Empidonagc hammondi, Baird, B. N. Am. p. 199, t. 76, f. 1'; Coues, Pr. Ac. Phil- 1866, p. 52',' 



Birds N, W. p. 257'; Key N. Am. B. ed. 2, p. 443 = ; Sumichrast, Mem. Bost. Soc. N. H. 



i. p. 557°; Baird, Brew., & Ridgw. N. Am. B. ii. p. 383'; Henshaw, U. S. Geogr. Surv. 



West 100th Mer. v. p. 362 ' ; Lawr. Bull. U. S, Nat. Mus. no. 4, p. 27 ' ; Ridgw. Ibis, 1886, 



p. 467 " ; Man. N. Am. B. p. 344 " ; Scl. Cat. Birds Brit. Mus. xiv. p. 232 '^ 



E, obscuro similis et forsan taud distinguendus, caudse rectrice utrinque estima pogoniis ambobus fere unico- 

 loribus. Long, tota 5-2, alae 2'8, caudse 2'3, tarsi 0'65, rostri a rictu 0'55, (Descr. exempl. ex Orizaba, 

 Mexico. Mus. nostr.) 



Eab. Western Noeth Ameeica, from the Lesser Slave Lake southwards ", — Mexico, 

 Sierra de "Valparaiso in Zacatecas {Richardson), State of Vera Cruz {Sumichrast^), 

 Orizaba [F. B. G), GinetaMountains {Sumichrast^) ; Guatemala, Calderas 7500 feet. 

 Pine-forest of Volcan de Fuego, between 10,000 and 12,000 feet {0. S. & F. B. G.). 



We are not at all sure that skins of this bird can always be distinguished from 

 E. obscurus, the point chiefly relied upon lies in the colour of the outer web of the 

 outermost tail-feather on either side, which in E. hammondi hardly differs from the 

 inner web, but in E. obscurus is always whitish ; moreover, E. hammondi is usually a 

 smaller bird than E. obscurus. We find, however, small birds with the outer web of 

 the tail*feather paler than the inner, so that it becomes very difficult to determine 

 accurately every individual. E. hammondi has the long narrow bill of this section 

 of Empidonax, so that we have little doubt that it is with E. obscurus that it should 

 be compared, and this is the opinion of both Dr. Coues and Mr. Ridgway, though 

 Mr. Henshaw considered that its affinity is with E. minimus ^. 



