1873.] 73 [Ridgway. 



APPENDIX. 

 Kevision of the Falconine Genera, Micrastur, Gerano- 



SPIZA AND RUPORNIS, AND THE STRIGINE GENUS, GlAUCIDIUM. 



Based upon specimens in the Museum of the Smithsonian Institution, the Phila- 

 delphia Academy of Natural Sciences, the American Museum, at New York, 

 the Boston Society of Natural History, the Museum of Comparative Zoology, at 

 Cambridge, and the Ornithological Cabinet of Mr. Geo. N. Lawrence. 



Genus Micrastur Gray. 



Brachypterus Lesson, 1837 (nee Kugel, 1794!). Type Falco brachy- 

 pterus Temra. 



Micrastur G. K. Gray, 1841. Same type. 



Carnifex Less., 1842 (nee Sundevall, 1836!). 



Climacocercus Cabanis, 1844. 



Climacourus Bonap., 1849. 



Rhyncomegus Bonap., 1853. 



Ch. Form of Nisus, i. e., wings short, rounded and concave, 

 tail very long, tarsi and middle toe long and slender, and cere as- 

 cending. A distinct ruff around the face, as in Circus ; inner webs of 

 the primaries with their edges soft and woolly, as in the Strigidce. 

 Bill much compressed, nearly twice as deep as broad at the base, the 

 culmen abruptly curved; commissure slightly lobed; end of lower 

 mandible with a rounded terminal outline when viewed laterally, but 

 in front divided by an angular notch ; gonys strongly convex. Cere 

 rather densely haired, the hairs on top recurved; nostril broadly oval, 

 or nearly circular, against the anterior edge of the cere. Orbital 

 region and superciliary shield perfectly bare, the latter very promi- 

 nent, and exposed for its whole length, as in Falco. Tarsus more 

 than twice as long as the middle toe, scarcely feathered below the 

 knee; its scutellae of a hexagonal form, and arranged in longitudinal 

 series; they are larger in front and behind than laterally, and 

 sometimes form a continuous frontal and posterior series of rather 

 quadrate plates; top of toes with transverse scutellse to the base; web 

 between base of outer and middle toes well-developed; claws of 

 normal form, well curved, and exceedingly sharp. Wing short, very 

 rounded, and very concave beneath, the primaries much bowed ; third 

 to sixth (usually the fifth) quills longest; first very much the shortest; 

 five outer quills with their inner webs cut (rather deeply sinuated). 

 Tail equal to, or longer than, wing, much rounded, or graduated. 



