1903. 



SYRINX OF THE ACCIPITRES. 



161 



are attached to the middle of the second bronchial semiring. The 

 first three bronchial rings are closely laid by each other and the 

 ti-acheal rings ; larger interspaces separate the ensuing bronchial 

 semirings ; but there is no wide membrana tympaniformis externa. 



Genus MiLvus. 



In this genus, at least in the species M. ictinus, the bronchi- 

 desmus is incomplete. There is no conspicuous membrana 

 tympaniformis externa. The intrinsic muscles are attached to 

 the second of the entirely free semirings, ^. e. those which are not 

 fused with the pessulus. The syrinx therefore is constituted on 

 the plan of that of Nisaetus. 



Genus Dryotriorchis. 



D. sjyectabilis is a Hawk with an altogether unusual form of wind- 

 pipe (text-fig. 18) : that is to say, unusual as to details, for it dis- 

 tinctly belongs to the Aquiline as opposed to the Falconine division 



Text-fiff. 18 



Syrinx of Dryotriorchis sj^ectabilis. X 3. 



of the group. In this genus the bronchial character of the syrinx, 

 suggested among the Aquiline forms, is more strongly emphasised 

 than in any other Accipitrine genus which I have had the 

 opportunity of examining. In fact this Hawk may be fairly 

 described as possessing a bronchial syrinx. This syrinx is, how- 

 ever, an exaggeration of the conditions occurring in such a form 

 as Nisaetus. In that genus and its allies four or five rings, which 

 Proc. Zool. Soc— 1903, Vol. II. No. XI. 11 



