438 RESIDUE OF EXTINCT BIRDS OF QUEENSLAND AS YET DETECTED, 



of which the basal side slopes downwards with a transversely 

 convex surface to a flat crescentic area embracing the rounded 

 contour of its foot. In this form it occurs more or less obviously 

 and symmetrically in Haliastur, Nisaetus, Astur, Baza, Circus, 

 and Lophoictinia, and even in Ninox among the Strigidce., but in 

 no other birds has it been recognised by the writer. The apparent 

 triviality of such a feature as this, though certainly diminished by 

 its restriction to and frequency in one family, would hardly lead 

 us to expect for it any great persistence in time, yet it is exhibited 

 in the fossil in even greater precision than in Haliaetus. Whether 

 then it be supported or otherwise by accompanying characters, it 

 must hold its own and stamp the fossil with the seal of the 

 Falconidce. It does, however, derive sufficient countenance from 

 the presence and position of a linear deltoid ridge on the ventral 

 aspect of the bone ; this, as usual in birds of prey, runs downwards 

 parallel with and near to the midline of the shaft. 



With guidance up to this point we have to be satisfied, for to 

 no extant genus can we find direction in the rest of the fossil's 

 structure. The head is narrow and remarkably prolonged upon 

 the pectoral ridge, towards which it descends uninterruptedly 

 without permitting the formation of an ulnar tuberosity (PI. xxiv., 

 fig. lb A). If we take the humeral head of a Menura, lessen 

 its curve and reduce the gibbosity of its ventral side, we shall 

 reproduce that of the fossil on a smaller scale ; and Menura alone 

 appears to represent the extinct hawk in this particular. The 

 form of the shaft is no less remarkable, and for its parallel we 

 must resort to Phalacrocorax. It is eminently trihedral, presenting 

 on its ventral aspect two faces, a flat anterior and a slightly convex 

 posterior surface. These meet in a median culmen, and this again 

 divaricates opposite the pneumatic foramen into two branches, the 

 one merging into the strong ridge supporting, in the Falconidai, 

 the radial tuberosity ; the other more subdued, but still distinct, as 

 it is in no other bird, goes to the ventral edge of the head (PI. xxiv., 

 fig. 16 B). The sub-tuberous pneumatic foramen is small, round, 

 and thick-walled ; the tunnel into which it opens proceeds unin- 

 terruptedly into the substance of the bone. Such are the generic 



