°i8 9 6 j Oberholser, The Mexican Forms of Certhia. •? I >i 



Habitat. — Mexico merid. et centr. ; Guatemala. 



Description.— No. 69835, U. S. Nat. Mus.; Volcan de Fuego, Guate- 

 mala, Nov. 18-20, 1873, 10200-1 2000 feet; Osbert Salvin. Ground color 

 of the upper parts dark sepia brown, the rump and upper tail-coverts very 

 dark tawny. Superciliary stripe, streaks on pileum, cervix and inter- 

 scapular region, bars and spots on wings, white, stronglv suffused with 

 rufous. The markings on head, hind neck, and back more indistinct than 

 in albescens; those of the last mentioned portion somewhat confluent. 

 Back with much infusion of tawny and chestnut ; the outer webs of the 

 tail-feathers with an edging of ochraceous. Chin and throat white, 

 washed with ochraceous ; crissum very pale tawny ochraceous, mixed with 

 white; remainder of lower parts dull gray, suffused and somewhat mixed 

 with rusty. 



A much richer, more fulvous tinge characterizes this race as 

 distinguished from the preceding. The light markings upon the 

 head and cervix are somewhat reduced both in number and size, 

 and together with those of the interscapular region are strongly 

 suffused with the prevailing rufescent tinge of the remainder of 

 the plumage, being thereby rendered noticeably less conspicuous. 

 The ochraceous or rufescent tinge below is quite marked in com- 

 parison with typical albescens, though the amount of rusty admix- 

 ture is decidedly variable. In some specimens, however, the 

 throat is apparently without the ochraceous tint, being nearly as 

 pure white as in albescens. The bird above described is perhaps 

 an extreme specimen, as in all of the others the dorsal streaks are 

 more grayish, often with a slight greenish tinge. 



In its most typical form this subspecies inhabits Guatemala and 

 southern Mexico, but the birds from central Mexico should appar- 

 ently be also here referred. Specimens of Certhia from Vera 

 Cruz, Puebla and southern Jalisco, though approaching albescens 

 in the rather lighter color of the markings on the upper parts, are 

 much darker below, and altogether are much nearer alticola. 



The foregoing remarks have been based upon a series of eight- 

 een specimens ; five of the form here distinguished as Certhia 

 familiaris albescens, and thirteen of Certhia f. alticola. Although 

 more material would of course have been desirable, yet that which 

 is now available seems sufficient to warrant the conclusions above 

 reached. 



Acknowledgment should be made to Mr. F. M. Chapman for 

 his kindness in permitting the writer to examine the series of 



