The hypoglossal nerve escapes by two small foramina on each side of the base of the condyle; external to these is the vagal foramen; still more external is the depression (ib. _a_) perforated below by the entocarotid, glossopharyngeal, and sympathetic, above by the tympanic vein. The entocarotid canal opens into the hind part of the sella or pituitary fossa: the vagal canal begins within the skull, above the hypoglossal foramina. The paroccipital carries the posterior surface of the skull downward and outward to a much greater degree than in any Dove, but to a less degree than in _Dinornis_. The Eustachian tubes impress the outer and fore part of the basisphenoid. The temporal fossæ (Pl. III.), in the present specimens, show the same contraction in proportion to their depth by which the original skull of the Dodo, compared with that of the _Dinornis_, ‘Proc. Zool. Soc.’ (1848, p. 3), differed from the larger extinct wingless bird. In the approximation of the postorbital process to the mastoid, _Didunculus_ shows a closer resemblance to _Didus_ than does _Goura_, in which the temporal fossa, besides being narrow, is shallow. The temporal muscle appears to spread its origin above the fossa upon the sides of the cranium, forward half an inch in advance of the postfrontal process, and backward to the outer angle of the superoccipital ridge. The parietal region is broad, flat, and short, as in _Dinornis_, not convex as in Doves; it is also impressed at its middle part by a shallow transverse groove, continued outward and forward of less depth and definition, so as to mark off the convex interorbital part of the swollen frontals. The outer side of the mastoid is convex, smooth, overhanging the tympanic cavity, and sending off a short process, the base of which is defined in one cranium by a transverse ridge in front of the anterior articular cup for the tympanic bone. A similar process is developed in _Didunculus_, not in _Goura_, where it is barely indicated. The presphenoid is compressed, but thickened and rounded below, where the palatines and pterygoids at their junction with each other abut against it: the pterygoid sends off a short process from the middle of its hinder border; but this is not met by a corresponding “pterygoid process” of the basisphenoid as in _Didunculus_.