I. _The Frontal Bones._--No. 1. The least transverse diameter, immediately behind the external angular processes, is 3″·6, and its greatest (at the coronal suture) about 4″·3. Longitudinal arc, 4″·1. The profile outline of the forehead is slightly receding; the frontal sinuses moderately developed; and the supraorbital border thin and acute, whilst the glabellar eminence is large and prominent. The bone is a good deal compressed on the sides, so as to have almost the appearance of having formed part of a cymbecephalic skull. The bone itself is thin, and probably without any _diploë_. No. 2 presents exactly the same characters, except that the longitudinal arc is greater, being 5″·3. The postorbital or least transverse diameter is 3″·4, and the coronal or greatest 4″·4. The frontal sinuses are well developed; the supraorbital ridge rather prominent, but thin and sharp; the external angular process prominent and thick. Glabellar eminence large and prominent. The nasals remain _in situ_, and project almost, if not quite, horizontally forwards, with a rapid curve at first, and then straight out. The general contour of the bone is exactly like that of No. 1, in which also, although the nasals are wanting, the position of the surface by which they were attached shows that they must in all probability have resembled those of No. 2. The _crista galli_ of the ethmoid, which is left _in situ_, is remarkably thick and high. No. 3 is a portion of a larger and wider bone, the postorbital diameter being at least 4″·0. The frontal sinuses are very large, but distinctly defined, as the remainder of the supraorbital border is not thickened. Owing perhaps to the greater prominence of the sinuses, the glabella does not appear so protuberant as in the other instances. The nasal bones remain and project forwards in the same curious fashion as in No. 2. The frontal crest on the inner surface is remarkably developed, being at least half an inch high, though it is separated by a wide notch from the equally strongly developed _crista galli_ of the ethmoid. No. 4, when the three bones of which it is composed are put together, consists of the greater part of the parietal region of the skull, to which, as before said, the last-described frontal may have belonged. The left parietal is quite perfect; and a considerable portion of the right also remains, together with the entire left temporal; so that a very sufficient estimate of the proportions of the parietal region of the skull can be obtained.