86 OSTEOLOGY [Parr IT. 
and appears to ascend ten lines and a half to its apex. The cramio-facial line is notched on each side, by 
the termination of the nasal fissure; the distinction between the mandibular and cranial segments of the 
nasal is least marked on the right side: the part of the latter, immediately behind the broad outer limb, 
is more inflated than the upper and inner angle; the expanded portion being defined by a semi-lunar 
groove. ‘The triangular frontal aspect of the prefrontal, from the compression of the anterior part of the 
cranium, is directed very obliquely outwards; the anterior edge beg much in advance of the posterior, 
which is anchylosed to the antorbital process; a deep fissure separates the anterior or inner margin from 
the ecto-nasal limb; the base forms the upper rounded border of the lacrymal groove, and terminates 
anteriorly in an obtuse projecting angle. This surface is perforated by numerous vascular apertures. 
The sub-crescentic supra-orbital tract is rough, and perforated by periosteal vascular foramina; a 
series of larger size extend from the notch on the antorbital process to the supra-orbital foramen or notch, 
and indicate its inner boundary; hence the supra-orbital plate appears formed, as it were, by a separate 
ossification of the periosteum extending outwards to protect the eyeball. The space in front of the semi- 
circular venous grooves is also minutely punctate, the apertures becoming larger anteriorly. The tabula 
externa of the pneumatic diploé, on the frontal slope, is thinned and inflated opposite the individual cells ; 
and some of these have opened out; these appearances indicate that the skull in question belonged to a 
domesticated mdividual. 
The parieto-mastoid tract is gently arched transversely, but ascends rapidly in the antero-posterior 
diameter. It is narrow mesially, but extends laterally so as to occupy two-thirds of the convex external 
edge of the cranium, behind the supra-orbital notch. The rhomboidal digastric impression occupies the 
posterior angle of this tract, its transverse diameter is less than one-fourth of the breadth of the cranium ; 
its posterior external angle corresponds to a slight groove on the mastoid process leading to the mastoid 
notch ; its broadly rounded inner and posterior angle is separated from the supra-occipital ridge by the 
hinder horn of the parietal surface ; a smooth narrow tract imtervenes between its anterior margin and the 
temporal notch, and is continued into the smooth external surface of the mastoid process ; the superior 
and anterior angle touches the pyriform muscular area which surrounds the crotophyte impression in 
front; the posterior border, as already mentioned, is separated from the occipital muscular surface by 
the smooth convex edge extending from the canalicular elevation to the mastoid notch. The crescentic 
crotophyte impression, forms a shelving entrance internally and anteriorly to the temporal notch; on the 
left side, a sharp ridge separates from the anterior limb of this surface, a triangular segment impressing the 
post-orbital process, with its base external. Surrounding the crotophyte impression in front and within, 
is a subpyriform excavation ; its apex is truncated on a level with the posterior margin of the temporal notch, 
whilst its rounded extremity is separated by a narrow scabrous tract, four lines in breadth, from the orbital 
margin, and is so abruptly sunk beneath the level of the frontal protuberance, as to lodge the poimt of the 
finger. This impression doubtless gave origin to a cutaneous nfuscle, dermo-mastoideus, which is inserted 
into the integument of the posterior surface of the neck; it would erect the feathers on the head of the 
Dodo, and push forward the hood-like cutaneous ridge. 
The anterior horn of the parietal tract sweeps round the dermo-mastoid impression to be continued 
into the rough supra-orbital space, bounding it externally. The parietal surface is variously marked by 
small vascular impressions, but is destitute of the foramina so abundant on the frontal slope. 
The anterior and lesser aspect of the cranium presents the deep olfactory fossee, separated mesially by 
the thin anterior prolongation of the interorbital septum, which rests below on the sphenoidal rostrum. The 
single small olfactory foramen, on each side, opens directly, with an inclination outwards, into the base of 
