(syn. Micrastur Ϯ Lined Forest Falcon M. gilvicollis) L. clamosus clamorous, noisy < clamare to shout; genus Circus de Lacépède, 1799, harrier; "Gen. XX. CLAMOSOCIRCUS gen. nov. Type C. gilvicollis (Vieillot) ... Size small; feet very much smaller than in Micrastur; tarsi more slender, with broad and regular scales in front; plumage regularly barred below in adults. ... CLAMOSOCIRCUS RUFICOLLIS (Vieillot) ... An adult male from Paraguay is figured on the plate accompanying pt. II. together with an adult male of C. g. guerilla from Guatemala. This plate is lettered with the generic name Climacocercus Cabanis (1845), but this name cannot be used for the present group as it is predated by Climacocercus Cabanis (1844), the type of which, as Dr. Wetmore points out to me, is M. brachypterus Temm. (= M. melanoleucus Vieillot). I therefore call the present genus Clamosocircus" (Swann 1925) (OD per Björn Bergenholtz).