Editorial note — Part 1.-- Vertebrata. (continued 3)

Of the frog is a cylindrical box, from which the otic capsules project conspicuously on either side. It contains only two ossifications in its cartilaginous substance (the sphen-ethmoid and the ex-occipital), being protected by the membrane bones, the parieto-frontals above and the parasphenoid below. In the mammal it is enormously inflated, and the otic capsules are imbedded in its wall. There are supra- and basi- as well as ex-occipital bones; the para-sphenoid is (? entirely) gone, and its place is taken by the basi- and pre-sphenoids, and the lateral walls contain fresh paired ossifications, the ali- and orbito-sphenoids-- all cartilage bones. The sphenethmoid is perhaps represented in part by the ethmoid. As a result of the inflation of the brain-case, the squamosal, which slopes downward and outward in the frog, and overlies the cartilaginous suspensorium (quadrate cartilage), has become a constituent of the brain-case wall, and slopes downwardly and in.