DEVELOPMENT OF THE SKULL IN THE MAMMALIA. 
79 
and left of the hind part of the vomer there is a bony plate; these are hind paired 
vomers (fig. 10,v.") ; they serve to unite the vomer, proper, with the ossifying ethmoidal 
masses, afterwards ; the principal or proper vomer is not carinate below either in this 
type, in the Armadillo, or in the Sloth (see Plate 2, fig. 1 ; Plate 3, fig. 9; Plate 5, 
fig. 6; Plate 6, fig. 9 ; Plate 8, fig. 8.). 
When it is carinate below, the vomer, resting upon the hard palate, keeps up the 
subdivision of the nasal passages, so far back; whereas in these Neotropical 
Edentates these passages open into each other close behind the snout. Now this state 
of things is not seen in the Palseotropical kinds, as I shall soon show, and as these 
latter agree in this respect with the Insectivora, and also, as in one of their Old 
World forms, the Aard-Vark, we have the exceptional “ interparietal ”—so large and 
universal in the Insectivora—it seems reasonable to suppose that we have in the Old 
and New World Edentata two “ suckers’’from some old “root-stock,” that separated 
from each other long since, diverging and breaking up, each into its own special sub¬ 
division, of which sub-division we have only two genera, representing two, families in 
the Old World, and many genera and several families—especially if we take in the 
extinct kinds—in the New World.* 
Manidal 
My materials for working out the skull in this family were as follows :— 
First Stage. Embryo of Manis, -? sp. ; 2f inches long, snout to root of tail; 
tail itself §• inch long (Plate 1, figs. 3, 4).f 
Second Stage. Embryo of Manis brevicaudata (from Ceylon ; procured for me by 
Mr. Ward) ; 4§ inches long, snout to root of tail; head If inch long; tail 
2f inches (Plate 1, figs. 5, 6). 
Third Stage. New-born young of Manis Temminckii; head 2f inches long. 
Fourth Stage. Adult Pangolin’s skull, Manis, -? sp. 
First Stage. — Embryo of Manis,-? sp. ; 2f inches long (Plate 1, figs. 3, 4). 
The skull of this very immature embryo (Plate 11, figs. 1-6) differs very greatly 
from anything I have as yet seen in the Mammalia; it has its endocranial parts as 
abortive as its ectocranial. 
* In the present state of my slow work I scarcely can hint at the relation of these Old and New 
World Edentata to the groups below and around them ; I feel sure, however, that the Aard-Vark is 
the nearest to the Insectivora, of any in the Order; and that the New World kinds, generally, and the 
Old World Pangolins, also, are nearer to the Monotremes than to the Marsupials. 
t The youngest Tatou ( Tatusia hybrida) was only If inch long from snout to root of tail (Plate 1, 
figs, 7, 8), but its development was twice as much advanced as this; the Pangolins, like the Aard-Vark, 
are very large at the time of birth. This embryo of the Pangolin, for which I am indebted to Dr. 
Gunther, is therefore my proper starting-point in tne study of the skull in the Edentata. In the 
Insectivora, Marsupialia, &c., I shall describe much earlier stages than this. But if time and materials 
serve, I hope, some day, to add an appendix to the present paper, giving earlier stages. 
