AET.19 CONCERNING BIEDS' TONGUES GAEDNEE 15 



Within the family there is no reliable basis for separation on 

 tongue form alone. The mergansers are recognizable as a separate 

 group, as are the heavy tearing tongues of the geese and swans, and 

 roughly the Fuligulinae may be distinguished from the Anatinae 

 by the number of lateral " teeth." But with the exception of certain 

 very odd types that mark special genera, as Ghloephaga and Cere- 

 opsis, or a characteristic wide tongue as in Spatula, there is often 

 doubt as to what genus and subfamily a single specimen should be 

 referred. 



Order FALCONIFORMES 



In this group the tongue is a heavy rasping organ. The Cathar- 

 tidae and the Vulturidae have a deeply curled organ, trough-shaped, 

 with the upcurled margins armed Avith strong rasping spines. These 

 range in size from the relatively small one of the buzzard, Gathartes 

 aura septentrionalis (fig. 38), to the large powerful object of the 

 condor, Sarcorauiphus gryphus and Gyps fulvus, with extreme uni- 

 formity of pattern. 



In the hawks the posterior border of the tongue may consist of 

 one row of spines or of many, and on this character they may be 

 divided into two natural groups; that is, the Buteonidae, with a 

 single row, and Falconidae, with many spines distributed over the 

 basal portion, as was first suggested by Beddard.^ 



Among the Buteonidae the following genera have been found to 

 present but a single row of spines posteriorly : 



Accipiter (cooperi, fig. 43). 



Astur. 



Elanus. 



Urospiza fasciata. 



Ictinia. 



Rupornis. 



Buteo. 



B. Uneatus elegans (fig. 12). 



B. borealis calurus (fig. 37). 



B. alMcatidatus (fig. 42). 



Pandion haliaetus has a single row, but occupies a family of 

 itself. 



The following Falconidae have been found to have many spines 

 distributed over the posterior portion of the tongue : 



Tinnunculus alaudarius. 



Milvago chimango. 



Hieracidea herigora. 



Polyborus (plancus, fig. 41). 



Falco. 



F. sparverius phalaena (fig. 39). 



Milvus. 



Circus {hudsonius, fig. 40) 



Leucopternis. 



Spizaetus. 



Archihuteo. 



Dryotriorchis. 



Morphnus. 



Asturina. 



Urubitinga. 



Oypohierax. 



» Beddard, F. E. On tlie Modifications of Structure in the Syrinx of the Accipitres, 

 with Remarks Upon Other Points in the Anatomy of That Group. Proc. Zool. Soc. Lon- 

 don, 1903, vol. 2, pp. 157-163. 



