130 BULLETIN 5 0, UNITED STATES NATIONAL IMUSEUM 



Genus ROSTRHAMUS Lesson 



Cymindes (not Cymindis Cuvier, 1817) Spix, Av. Bras., i, 1824, [=1825-1826?], 

 7. (Type, bj' monotypy, C. lencopygris Spix'^ Herpdotheres sociabilis Vieillot.) 

 (See Oberholser (Proc. Biol. Soc. Washington, xxxv, 1912, 79), who con- 

 siders Cymindes Spix available as the proper name for this genus. It is 

 clearly a misprint or "emendation" of Cymindis and therefore should not be 

 taken up; spelled Cymindis by Spix on pi. 2 and in index.) 



Rostrhamiis Lesson, Traits d'Orn., 1830, 55. (Type, by monotypy, R. niger 

 Ijesson = Herpetotheres sociabilis Vieillot.) 



Rosiramus (emendation) Lesson, Trait6 d'Orn., 1831, G58. — Burmeister, Reise 

 durch La Plata-Staaten, ii, 1861, 435. 



Rosihramus (emendation) d'Orbigny and Lafresnaye, Synop. Av., 1837, 3. — 

 Lesson, Rev. Zool., ii, 1839, 133.— Sharpe, Cat. Birds Brit. Mus., i, 1874, 

 327. 



Rostrhamas (emendation) Kaup, in Jardine's Contr. Orn., 1849, 112. 



Rostrohamns (emendation) Le Moine, Orn. Canada, pt. 1, 1860, 87. 



Rostrihamus (emendation) Bertoni, Aves Nuevas Paraguay, 1901, 171. — Berg, 

 Com. Mus. Nac. Buenos Aires, i, 1901, 287. 



Hamirostrum, (emendation) Sundevall, Tentamen, 1873, 109; Ofv. Svensk, 

 Vet. = Akad. Forh. (Disp. Accip. Hemeroharp.), 1874, 36. 



Hemirostrmn (emendation) Giebel, Thes. Orn., iii, 1877, 810. 



Rostrhamphus (lapsus?) Chapman, Bull. Amer. Mus. Nat. Hist., xxxvi, 1917, 249. 



Medium-sized Accipitridae (wing about 325-370 mm.) with the 

 maxilla very narrow and siclde-shaped, culmen two-fifths to nearly 

 three-fifths as long as tarsus, the latter only about one-seventh as 

 long as wing and less than one-third as long as tail, the tail nearly 

 half as long as wing, its tip emarginate, the upper tail coverts and 

 base and tip of tail white. 



Maxilla very slender (its greatest depth at base equal to less than 

 one-fourth the length of culmen, and slightly less than its width at 

 same point), sickle-shaped, the tomia regularly concave throughout; 

 mandibular tomium strongly convex throughout, the gonys straight 

 or even faintly concave, descending, rather than ascending, terminally; 

 cere very broad on top, its anterior outline straight across base of 

 culmen thence forming a nearly straight line obliquel}^ downward and 

 backward; nostril narrowly elliptical or fusiform, obliquely horizontal; 

 rictus on line (vertically) with anterior angle of eye. Wing long and 

 broad, the longest primary exceeding distal secondary by about two- 

 fifths the length of wing; fourth or fourth and fifth primaries longest, 

 the first (outermost) shorter than seventh; four outer primaries with 

 inner webs sinuated. Tail a little less than half as long as wing, its 

 tip slightly emarginate. Tarsus about one-seventh as long as wing, 

 between one-fourth and one-third as long as tail, the upper portion 

 feathered in front and one side for about two-fifths its length, the 

 nude portion of the acrotansium with a continuous series of broad 

 transverse scutella, the tarsus covered elsewhere with small hexagonal 

 scutella, those of the planta tarsi larger and more quadrate, arranged 



