AOOIPITEES 479 



The syrinx is not remarkable in form. Anteriorly the 

 last three tracheals are fused medianly ; posteriorly the fusion 

 is more extensive, and includes the first bronchial semi-ring. 

 The second bronchial semi-ring is in front close to the first ; 

 behind it is united with the third, upon which latter are 

 inserted the intrinsic muscles. 



The skull is accipitrine and not strigine. The descending 

 process of the lacrymals, however, is firmly and entirely 

 blended with the ectethmoid, but the former bone has no 

 backwardly projecting frontal portion, let alone a separate 

 ossification at the end of it, such as is met with in some 

 Accipitres. The vomer is long and ^nds in front in an olive- 

 shaped swelling which fits in between, but is not attached 

 to the diverging limbs of the anteriorly fused maxillo- 

 palatines. 



The ring of the atlas isincoToplete in the middle line above ; 

 there are fifteen cervical vertebra. The hsemapophyses are 

 very feeble on the earlier cervical vertebrae ; they commence 

 on CIO, where they are double ; they are strong over the last 

 cervical and the first three dorsals, where they end. Six 

 ribs reach the sternum, of which the first four have uncinate 

 processes. Both the tibio-tarsus and the tarso-metatarsus 

 have a bony bridge for tendons ; the latter has one behind 

 as well as in front. 



This bird possesses a scapula accessoria in the glenoid 

 capsule, the significance of which as a point of affinity with 

 the owls is marred by its occurrence in toucans, &c. (see p. 192) . 

 The coracoids slightly overlap, as in some Accipitres. 



"Whatever may be thought about Paiidion, it is clear 

 that the separation of the secretary bird to form a distinct 

 family, Serpentariidse, is perfectly justifiable.' 



Serpentarius has basipterygoid processes, a,nd its muscle 

 formula is BXY + . 



The tensor patagii &re?;*s is more stork or crane hke than 

 accipitrine, and indeed resembles Cathartes in the presence of 



• The claims of Polyboroides to be a member of this family have been dis- 

 missed by Milne-Edwaeds (Hist. Nat. Madagascar) and myself (loc. cit. on 

 p. 474). 



