26 BANGS — COSTA RICAN BIRDS eyo 
Chaetura cinereiventris guianensis Hartert, and Chetura fumosa 
Salvin. Lately Hellmayr* has said that Costa Rican birds were 
wrongly referred to Chetwra fumosa (originally described from 
Veragua), and has named, as a new subspecies, Chetura cineret- 
ventris pheopygos from eastern Costa Rica,— type locality, Carrillo. 
Probably Hellmayr had no specimens from the Pacific side of the 
Cordillera in Costa Rica before him when he wrote. 
In reality two very distinct species (in addition to Chetwra 
gaumert Lawr. and C. vauai (Towns.)) inhabit Costa Rica. One, 
Chatura cinerewventris pheopygos Hellmayr, a form closely related 
to both C. cinereiventris lawrencei Ridg. of Grenada and C. cine- 
rewentris guianensis Hart. of Guiana, Venezuela, Trinidad and 
Tobago, occupies eastern Costa Rica. I have specimens from 
Carrillo — the type locality — and from Juan Vinas. 
The other, Chatura spinicauda jumosa (Saly.), a northern form 
of C. spinicauda, ditfermg from the typical bird of Cayenne and 
Guiana in wider gray band across rump and slightly darker under 
parts, occupies the Pacific slope of Costa Rica, and extends thence 
south through Veragua and Chiriqui to northern Colombia and 
Amazonia (Para and Santarem). I have a series of skins from 
Pozo Azul Pirris. 
From one another these two Costa Rican swifts are easily told; 
C. cinereicauda phaopygos has a dark gray rump, with the upper 
tail coverts of practically the same color, and the belly dark brown; 
C'. spinicauda jumosa has a pale gray rump, with the longer upper 
tail coverts black and the belly blackish. 
The case of these two swifts is but another mstance of that 
extraordinary development of bird life in Costa Rica, where the 
Atlantic (or perhaps better Caribbean) slope of the main cor- 
dillera is inhabited by one form, and the Pacific slope by another. 
Pachyrhamphus versicolor costaricensis subsp. nov. 
Type, from Irazv, Costa Rica, o adult, no. 17,089, coll. of E. A. and O. 
Bangs, collected Sept. 6, 1898, by C. F. Underwood. 
1 Bull. British Ornith, Club, Vol. XVI, No. CXXIV, p. 83, May 8, 1906. 
