158 



JVIR. F. E. BEDDARD ON THE 



[June 16, 



ness or incompleteness of the bronchidesmus is a feature which 

 apparently differs from species to species. In F. feldegcji I find 

 that the membrane is incomplete, that is to say it does not extend 

 right up to the bifurcation of the bronchi. In F. sacer and 

 F. biarmicus, on the other hand, the bronchidesmus is quite 

 complete. Upon other species I am unable to report. 



Genus HiERACIDEA. 



This genus, represented for me by the species IT. herigora alone, 

 has a syrinx belonging quite to the same type as that of Falco. 

 In fact a general description would apply equally well to both, an 

 obvious justification of the close alliance usually asserted to exist 

 between them *. 



Genus MiLVAGO. 



This genus, as represented by Milvago chimango (text-fig. 16) 

 and M. chimachima, is essentially Falconine in the characters of 

 its syrinx, and does not appear to me to come nearei' to Polyhorus 

 than to Falco. 



Text-fig. 16. 



Syrinx of Milvago chimango, lateral view. X 2. 



The first bronchial ring is very thick, especially posteriorly, where 

 it cui-ves down and bends forward ; it is to this piece that the 

 intrinsic muscles are mainly attached, though they are also 

 inserted into the membrana tympaniformis externa. It is, I take 

 it, the homologue of the thickening of the membrana tympani- 

 formis which is so characteristic of Falco. 



Genus Herpetotheres. 



Herpetotheres cachinnans has a syrinx which is constructed upon 

 the Falconine plan. 



* I may remark, however, that the backwardly directed papillae upon the tongue 

 are shorter than in any Falco. 



