1873.] OWEN" DENTIGEK0T7S BIRD. 513 



parietal region (ih. 7) is smooth, transversely arched, and feebly 

 impressed by the upper part of the crotaphyte fossa (figs. 1 & 2, «) 

 opposite the middle of the occipital region. 



The breadth of the cranium here is 1 inch 9 lines (0-045 m.) ; the 

 length from the lateral occipital ridge to the hind margin of the 

 orbit is 7| lines (0-016 m.). If a transversely curved fracture 

 of the upper part of the cranium had coincided with a coronal 

 (fronto-parietal) harmonia, the fore and aft extent of the coalesced 

 parietals at their median (sagittal) suture would be 5| lines (0 - 012 m.). 

 It is singular that a second fracture of the cranial roof should 

 have commenced behind where the interfrontal suture terminated, 

 and have extended forward to opposite the middle of the orbit ; but 

 this fracture soon quits the median line and inclines to the right ; it 

 is also complicated with a shorter posterior fracture starting from 

 the transverse one simulating the coronal suture, but which curves 

 unsymmetrically more forward on the left than on the right side. 



The frontals, moderately convex transversely at their back part, 

 become flat and then slightly concave in that direction as far as the 

 fronto-nasal suture (PI. XVI. fig. 4, n,/, «) ; this is not a fracture, or 

 but partially so at its outer ends. 



The length of the frontal part of the cranium is 2 inches (0-050 m.) ; 

 the least breadth of the interorbital tract is nearly 6 lines (0-012 m.); 

 the extent of the frontal suture is 9 lines (0-020 m.). The antor- 

 bital process of the lacrymal (fig. 2, 73) is less mutilated on the left 

 side of the fossil, which gives an appreciable idea of its size and shape. 



Both fore and hind boundaries of the orbits (PL XVI. figs. 1,2,4, o) 

 are partially broken away; but the antero-posterior diameter of 

 those cavities seems to have been 1 inch 2 lines (0-030 m.) ; the 

 vertical diameter is 1 inch 1 line (0-027 m.) ; they are of an oval 

 form, with the. small end forward. There is no trace of a depression 

 for a superorbital gland; the upper border of the eye-chamber is 

 thin, not to say sharp. 



In the basal portion of the upper mandible here preserved (figs. 1, 

 2, 4, 15,21,22) there is no remaining trace of suture to mark the boun- 

 daries of the nasal, premaxillary, or maxillary bones. 



An upper tract (fig. 4, 15), flattened at its hind part, is defined by 

 two obtuse linear risings converging from the ends of the fronto- 

 nasal suture rapidly, then bending forward, broadening and con- 

 verging gradually till lost in a median transverse convex ridge or 

 tract (22), 2 lines (0-004 m.) broad at the anterior fracture ; the 

 breadth of this mid tract, where flat, at the beginning of the lines 

 of minor convergence, is 4 lines (0 - 008 m.). 



The sides of the base of the upper mandible slope outward as 

 they descend to a longitudinal groove (figs. 1 & 2, g), with a slight 

 curve concave downward, below which the upper jaw-bone descends 

 vertically to the alveolar border. 



The extent, lengthwise, of the upper beak-bone here preserved 

 is, on the left side (fig. 2), from the end of the fronto-nasal suture, 

 1 inch 6 lines (0-037 m.), on the right side (fig. 1) 1 inch 1 line 

 (0-027 m.) ; the vertical diameter of the base is 9 lines (0-020 m.)» 



