Cu. I.] OF THE DODO. 75 
XI. The presence of a single mesial supra-occipital aperture above the foramen magnum, 
for the transmission of a vein, which arises from the muscles of the neck, and joins the posterior 
cerebellar sinus. Among the Raptores, it occurs in some Owls, but I have not seen it in any 
other family of birds. Its co-existence in the Dodo with other indications of affinity to the 
Columbide, shows the value of apparently trivial characters in determining the position of 
an anomalous form. 
XII. The general puewmaticity of the cranial vault is greater in Pigeons, and the prefrontals 
and sphenoidal rostrum are usually much more expanded than in the Vulturide and Cathartes. 
In these respects the Dodo resembles the Columbide, and differs remarkably in the bullose 
appearance of the prefrontal, and in the breadth of the rostrum, from the typical raptorial 
birds. The Pterocles also approaches the Columbidze in these characters. 
XIII. In the dower jaw, the curvature of the rami; their union at a more or less angular, 
short and ascending, symphysis; the separation of the dentary, and, in some cases to a late 
period, of the opercular elements ; the presence of the interangular foramen in certain genera ; 
the large triangular digastric, or basal, facet; the small area of the temporal and pterygoid 
impressions ; and the differences in the form of the articular surface, corresponding to those 
already alluded to, in the inferior surface of the tympanic, distinguish the lower mandible, in 
the Columbidz from that in the Vulturide and Cathartes: in the latter, however, the lower 
jaw is more curved than in the less aberrant Raptores. We shall afterwards see how these 
important differences are repeated in the Dodo. The development of the basal angles of the 
digastric facet into the posterior and internal angular processes, so characteristic of the 
typical Rasores, is observed in Pterocles. 
The family characters of the skull in the Columbide, just enumerated, are derived from 
the consideration of parts, important either in a physiological, or morphological, point of 
view. One or more of them may be absent in aberrant members, or be common to different 
types; but the whole, or a majority of them, occurring in the skull of an extinct form, would 
justify us in assigning to it a place among this interesting and extensive group. 
Before proceeding to a more minute description of the skull of the Dodo, and to a com- 
parison of it with that of other Pigeons, we may recapitulate shortly, those important differences 
which warrant us in restricting such comparisons to the members of the Columbine group. 
The skull of the Dodo differs from that of the Vulturide, in the relatively small and 
feebly uncinated core; in the elongation of the external nasal orifice, and absence of the 
ossified scale; in the great relative size of the maxillary bone; in the obliquity of the 
zygoma; in the form of the mandibular surface of the tympanic ; in the form of the palatine 
bone; in the absence of the ossified septum narium; in the absence of the vomer; in the 
form, and minute configuration, of the lower jaw ; in the anchylosis of the prefrontal, and 
obliteration of the prefronto-ethmoidal fissure; in the greater breadth of the interorbital 
region, and absence of the os superciliare ; in the small area of the crotophyte impressions, 
and the great relative size of the digastric surface; in the existence of the mesial supra- 
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