204 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvii. 



the Straits of Magellan are identical with those from Buenos Aires, 

 but Chilean specimens, though heretofore always considered identical, 

 prove to be different from either. 



All the names above quoted are undoubted synonyms of hornensis, 

 as their descriptions and localities show, thus leaving the bird from 

 central Chile without a subspecihc designation. The Troglodytes 

 magellanicus oi Gould is from the Straits of Magellan; Troglodytes 

 pallida Lafresnaye and d'Orbigny is from Patagonia; Thrlothorus 

 rosaceus Lesson from La Plata (and Chile); while Troglodytes hortensis 

 Gray is a variant or emendation of Lesson's hornensis. 



TROGLODYTES MUSCULUS ACOSMUS, new subspecies. 



Chars, suhsp. — Similar to Troglodytes viusculus hornensis, but paler 

 above, the rump more rufous; lower surface with rather more of 

 ochraceous tinge. 



Geographical distribution. — Central Chile. 



Description. -Ty\^(^, No. 148094, LT.S.N.M.; Chile; E. C. Reed. 

 Upper parts broccoli brown, becoming slightly rufescent posteriorly, 

 and shading into dull rufous on the upper tail-coverts, which, with the 

 back, are very faintly barred with dusky; tail dull rufous, with many 

 narrow bars of blackish; exposed surface of closed wings like the 

 back, but, with the exception of the lesser coverts, rather more ochra- 

 ceous, and narrowl}' barred with fuscous; lores and sides of head dull 

 brownish white, mixed with brownish and buft'y; lower surface pale 

 buffy isabella color, whitish on throat and center of abdomen, darkest 

 on sides, flanks, and crissmii, which last has a few rather indistinct 

 blackish spots. Length of wing, 56 mm.; tail, 49 mm.; exposed 

 culmen, 12 mm. ; tarsus, 16 mm. ; middle toe, 11 mm. 



All the characters which separate this form from Troglodytes m. 

 hornensis are much more pronounced in young than in adult birds. 

 From musctdus and tecellatus it differs in its paler upper parts, its 

 much lighter and more isabelline lower surface, as well as from the 

 former in much less spotted crissum. It may be readily distinguished 

 from Troglodytes m. rex by its strikingly isabelline lower surface. 



TROGLODYTES MUSCULUS HYPAEDON (Sclater). 

 Troglodijtes hypaedon Sclateb, Proc. Zool. Soc. Lond., 1861, p. 128. 



Type locality. — Oaxaca, Mexico. 



Geographical distribution. — Southern Mexico (Oaxaca and Yucatan) 

 to Guatemala. 



Although commonly considered identical with intennedius of Costa 

 Rica, the birds from southern Mexico exhibit easily recognizable dif- 

 ferences which entitle them to a subspecific name, being darker and 

 much more strongly rufescent, parti(;ularly on the lower surface. 



