94 PROCEEDINGS OF UNITED STATES NATIONAL MUSEtTM. [1885. 



Adult (type, Ko. 51388, Mazatlan, Mexico, February, 1868 ; F. Bisch- 

 off) : Above, pure French-gray, somewhat paler and more ecru on the 

 primaries. Pileum (except forehead and fore part of the crown) inckid- 

 ing occipital crest, black, with a glaucous or chalky cast in certain 

 lights. Forehead, pale grayish buflfj superciliary and postocular re- 

 gions and feathers bordering the base of the gular pouch, white ; sides 

 of head pale drab or grayish buff, passing gradually into deeper, more 

 pinkish, buff on the neck, the whole foreneck, including jugular plumes, 

 clear, deep vinaceous-buft', or pinkish-buff. Breast, abdomen, anal re- 

 gion, and lower tail coverts, rich vinaceous-cinnamon, lighter and more 

 buffy on the abdomen, duller and more olivaceous on the tibiae. Lining 

 of the wing dull black ; edge of wing buff", becoming jialer on the carpo- 

 metacarpal region. Sides and flanks blackish-slate, with a strong glau. 

 cous or chalky cast in certain lights. Gray of the back separated 

 from the light drab or grayish-buff' of the neck by a narrow bar of 

 black. Wing, 10.50; tail, 4.80; culmeu, 3.20; depth of bill, .95; 

 width of bill, 1.75 ; tarsus, 2.75 ; middle toe, 2.35. 



Twelve examples, from various parts of southern and western Mexico, 

 Guatemala, Nicaragua, Costa Rica, and Veragua, differ constantly and 

 conspicuously from two South American specimejns (one from the mouth 

 of the Amazon, the other from British Guiana) in the characters pointed 

 out above. The specimen described and selected as the type of the new 

 species is the lightest colored example among the twelve. A binomial 

 appellation is in this case preferred to a trinomial, for the reason that 

 there is no indication of i^robable intergradation, the most southern 

 specimen of the Central American form. (from Veragua) being, on the 

 contrary, the darkest of the whole lot. 



The species is named in honor of Senor Don Jose C. Zeledon, the ac- 

 complished ornithologist, of San Jose, Costa Rica. 



DESCRIPTION OF A NEW HA"WK PROM COZUMEL. 

 ^ ' By ROBERT RIDO^VAY. 



-Rupornis gracilis, sp. nov. 



Sp. char. — Similar to R. rujicanda griseicauda, but decidedly smaller, 

 and with the thighs and under wing-coverts nearly or quite immaculate, 

 instead of distinctly barred and spotted, respectively. Wing, 8.00-8.80 

 (average of ten specimens, 8.44) ; tail, G.00-G.30 (average, 6.13); culmen, 

 .60-.72 (average, .67) ; tarsus, 2.20-2.40 (average, 2. '3); middle toe, 1.05- 

 1.20 (average, 1.17). 



Hab. — Cozumel I., Yucatan. 



Compared with eleven specimens of R. rujicavda griseicauda from va- 

 rious parts of Mexico, including four from Yucatan, the Cozumel birds; 

 are found to differ constantly in the characters pointed out above. Thei 

 measurements of the series of R, griseicauda are as follows : Wing, 8.70- 



