BIRDS OF NORTH AND MIDDLE AMERICA. 827 



[Tetragonops]frantzn Sclater and Salvin, Nom. Av. Neotr., 1873,110. 



Panfrantzii Richmond, Auk, xvi, Jan., 1899, 77, in text. 



Semnornis frantzii Richmond, Auk, xvii, April, 1900, 179, in text. — Ferry, Pub. 



146, Field Mus. Nat. Hist., Orn. Ser, i, no. 6, 1910, 265 (Coliblanco, Costa 



Rica, habits). 

 Dicrorhynchus frantzii Carriker, Ann. Carnegie Mus., vi, 1910, 571 (Burgos de 



Irazu, Carrillo, La Estrella de Cartago, Azahar de Cartago, Cariblanco de 



Sarapiqui, La Hondura, etc., Costa Rica; habits). 



Superraxnily E,-A.]y[I»IIA.STir)ES. 

 THE TOUCANS. 



"^Rhamphastidae Cabanis, Wiegmann's Archiv fiir Naturg., 1847, pt. i, 348 



(includes Capitones). 

 =Rhamphastid£e Fuerbringer, Unters. Syst. Nat. Vog., ii, 1888, 1391. 

 =Rhamphastides Sharpe, Rev. Classif. Birds, 1891, 83; Hand-list, ii, 1900, 189. 



Desmognathous, scansorial (zygodactyle) Coraciiformes, related to 

 the Capitones but differing in absence or great reduction of after- 

 shaft, desmognathous (instead of gegithognathous or schizognathous) 

 palate, truncate vomer, highly specialized bill, the last very large 

 (always longer than head, sometimes nearly as large as body), with 

 distinctly decurved culmen, more or less strongly uncinate maxilla, 

 and peculiarly light construction, and with caudal muscles and 

 terminal caudal vertebrae peculiar." 



The Ramphastides constitute a well-circumscribed group of 

 zygodactylous Coraciiform, or, more properly speaking, Picine, 

 birds, very closely related structurally to the Capitones (Barbets), 

 but differing from the latter in the several anatomical characters 

 pointed out above, and externally in the great development of the 

 beak, which m some members of the typical genus, Ramphastos, 

 exceeds the body in length and almost equals it in bulk. In this 

 extraordinary development of the beak the Ramphastides resemble 

 somewhat the anisodactylous Bucerotes (Hornbills), of the Old 

 World tropics, but the beak is never surmounted by a casque 

 or accessory structure, such as birds of the latter family almost 

 invariably present. Although apparently so unwieldy, the toucan's 

 beak is exceedingly light, the whole interior consisting of a network 

 of bony fibers so arranged as to produce the maximum of strength 



« In examining the caudal vertebrae, it will be found that the six basal ones are 

 articulated by ball-and-socket joints and connected with the last ones, which are 

 anchylosed, by a synovial joint, and can be bent dorsad till their superior spines 

 touch the sacrum, while the broad and large transverse processes almost wholly 

 prevent lateral motion. The muscles, therefore, which in other birds turn the tail 

 sideways, in the toucans becopie assistants to the true elevators of the tail; for when 

 the latter have bent it upward sufficiently, the former become dorsad of the center of 

 motion, causing the jerk of the tail [a motion of that member exceedingly character- 

 istic of the toucans] by suddenly combining with the elevator muscles. (Stejneger, 

 Stand. Nat. Hist., iv, 1885, 415, 416.) 



