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Vol. 6,'p. 77-8^^ April 7, 1924. 



Occasional Papers 



OF THE 



Boston Society of Natural History. 



THE IDENTITY OF TROCHILUS RUCKERI Bourcier. 



BY OUTRAM BANGS AND THOMAS E. PENARD. 



For a long time the name Threnetes ruckeri, based on Trochilus 

 ruckeri Bourcier (Proc. Zool. Soc. London, 1847, p. 46) has been 

 used for a Costa Rican hummingbird of which a southern form, 

 inhabiting Ecuador and western Colombia, has borne the name 

 Threnetes fraseri (Gould). Bourcier's description, however, does 

 not agree with the northern form, a fact already discussed by 

 Hellmayr (Proc. Zool. Soc. London, 1911, p. 1177), Simon (Hist. 

 Nat. Trochil., 1921, p. 250), and Todd (Ann. Carnegie Mus., vol. 

 14, 1922, p. 271). We fully appreciate the reluctance of these 

 authors to make any change affecting nomenclature until the type 

 in the old Loddiges collection might be examined. Such an exam- 

 ination, if possible, would be highly desirable. On the other hand, 

 we believe that Bourcier's description so clearly applies to the 

 southern form now known as Threnetes fraseri, that we cannot con- 

 ceive in what manner an investigation of the type could possibly 

 affect the situation. Bourcier says definitely that the under parts 

 of the body are gray black, bronzed, that the head, neck, scapulars, 

 back, and tail-coverts are shiny dark green, and that the middle of 

 the tail is blue black. These characters all apply to the southern, 

 not to the northern bird; and we, therefore, do not hesitate to at- 

 tach the name ruckeri to the form which is currently known as 

 fraseri. 



The Costa Rican bird being thus without a name, we propose to 

 call it 



Threnetes ruckeri ventosus, subsp. nov. 



TypCf adult S^, Museum of Comparative Zoology, no. 116,624, from Pozo 

 Azul, western Costa Rica, 21 February, 1898; collected by C. F. Underwood. 



Svhspecific characters. — Similar to Threnetes ruckeri ruckeri (Bourcier) of 

 western Ecuador, but upper parts bronzy green instead of shiny grass-green; 

 middle portion of the tail-feathers (except the middle pair) dull blackish 

 without any bluish or purplish tint; belly pale, buffy gray. 



Measurements. — Type, adult cT: wing, 60.0; tail, 35.5; exposed culmen, 29.5. 



Remarks. — Hellmayr (loc. cit.) has already called attention to 

 the fact that the size of the buffy throat-spot is not diagnostic be- 

 cause it varies with the age of the individual. This we find to be 



