522 NOTES ON COSTA RICAN BIRDS CHERRIE. 



However, in making a comparison of the specimens with Mr. Sharpe's 

 descriptions and with the other specimens in the National Museum col- 

 lection, 1 was much puzzled, not only in regard to theCosta Rica exam- 

 ple, but also with examples of the species (in a comprehensive sense) 

 from Veragua, Panama, and Santa Marta, CoJombia. Mr. Eidgway has 

 greatly aided in making clear the comparative differences in placing at 

 my disposition his unpublished manuscript and published notes on the 

 very birds I have before me. In an article published in the Proceed- 

 ings of the Boston Society of Natural History, Mr. Eidgway points 

 out the difference between the type of T. fasciativentris and the Santa 

 Marta specimen as being greater than that between the latter and the 

 Panama specimens, and equivalent to the resemblance between Pan- 

 ama and Santa Marta examples as compared with Costa Eican and 

 Veraguan specimens. Mr. Eidgway then says: ''■ T. melanogaster may, 

 however, be distinguished by the pale rusty brownish, instead of white 

 bars on the under tail-coverts, and much less distinct (sometimes quite 

 obsolete) bars on the sides, flanks, and abdomen." Then "tberecanbe 

 no question, however, that this form grades directly into the Panama 

 form, which in all probability is only a local race of fasciativentris.^^ 



With this latter view I can hardly agree, there being other differ- 

 ences overlooked by Mr. Eidgway that seem to me to very clearly sep- 

 arate tlie birds as species. These differences consist in the Costa Eican 

 and Veraguan specimens having a rufous tail (somewhat paler than the 

 back) barred with black; whereas the Santa Marta and Panama birds 

 and tjYiQ of fasciativentris have the tail dusky, narrowly banded with 

 pale fulvous (Eidgway MSS). Also the bands on the upper tail-coverts, 

 primaries, and secondaries in theCosta Eican and Veraguan specimens 

 are obsolete or barely perceptible, to be seen only in certain lights. In 

 the Panama and Santa Marta examples these bands are very distinct; 

 not so distinct, however, in the type of T, fasciativentris. 



As Mr. Sharpe's descriptions of T. fasciativentris and T. melanogaster 

 appear to me somewhat faulty and misleading, I will present here, from 

 Mr. Eidgway's manuscript, descriptions of the type of T. fasciativentris 

 and a Costa Eican example of T. melanogaster : 



Thryothorus fasciativentris. 



Sp. Char.— Adult (Type, No. 2658, Lafresnaye Coll., "Bogota"): 

 "Above light Vandyke-brown, somewhat tinged with russet (lighter and 

 much duller than in No. 34095,U. S. Nat. Mus., from Sta. Marta), the pileum 

 decidedly duller (the feathers much worn, however) ; * secondaries with- 

 out the faintest indications of bars, and edges of primaries with only the 

 slightest possible suggestion of bars, discernible only on the closest in- 

 spection ; tail dusky, narrowly banded with pale fulvous, the bars con- 

 fined to outer webs (where extending to shafts), the inner webs, even of 



* A few scattered feathers, evidently of newer growth, are very simihir in color to 

 those of the back. 



