DEVELOPMENT OF THE SKULL IN THE MAMMALIA. 
101 
I have, moreover, to begin the description of this type of skull under an impression, 
which I believe is not prejudiced, that Orycteropus comes nearer the Marsupials and 
the lower Insectivores, and is further from the Monotremes, than the other Old 
World Edentates—the Pangolins. The whole of the New World Edentates, whether 
toothless, or with an imperfect dentition, appear to be like the Pangolins, upgrowths 
from the Monotremes. 
Unfortunately, I cannot bring the evidence for these views forward, now; but the 
papers on the skull of the Insectivora and Marsupialia will follow, next, upon the 
present. 
The complex structure displayed in the lower view (Plate 14, fig. 1), if traced out 
point by point, will show how much unlikeness there is between the only two remaining 
types of Old World Edentates. The face is long, the measurement, even now, of the 
base shows the tract in front of the fore margin of the presphenoidal territory to be 
twice the extent of the tract behind that point. Here the development of the jaws 
hardly suggests any change from that of the ordinary typical Mammals, with their 
well-developed sets of teeth, all round. The alinasal cartilages and nostrils 
( cil.n ., e.n.) are very peculiar, and quite unlike what I have lately been describing. 
Here the nostrils are anterior, and the intervening alee, after spreading out into 
projecting folds and processes, suddenly narrow in, and then project again right and 
left, the projection being caused by a peculiar and large narial valve ( n.v .). A deep 
fissure—not a solution of continuity of the cartilage—runs across, below, arching 
backwards a little in front of the premaxillaries (px.) ; and a median groove runs 
forward from this part to the end of the snout, the converging folds of the floor in this 
front part being elegantly crescentic—back to back. The part behind the transverse 
arched groove soon opens out, right and left, where it gives off the recurrent cartilages 
(fig. 5, rc.c.) ; I shall describe these parts soon. 
In this developing skull there is a palatal character seen at once, which is perma¬ 
nent in the curiously arrested skull of the Pangolin, this is the imperfect desmognathism 
of the palate, in front, exposing the vomer ( v .). As to the character of the bones 
covering the endocranium, they are very unlike those of Armadillos, Sloths and 
Pangolins, not thick and cellular, but thin and fibrous, very much like those of the 
Insectivora. The premaxillaries (px.) have retained their normal size, notwithstanding 
their loss of teeth ; the alveolar edge is a thick tract, with a lanceolate outline, and 
higher Mammalia, e.g., Lamb, Calf, &c .; but on my first, and very casual, look at the British Museum 
spirit-specimen, of the same age as this, I mistook it for the young, from the pouch, of some large kind 
of Kangaroo. 
The head, only, of this single stage, as worked out here, will be fruitful of suggestions of relationship, 
which point to quite other quarters than those just mentioned, which are, manifestly, somewhat fanciful. 
There are two species of this isolated, unique genus, namely, 0. capensis and 0. cethiopicus (see Proc. 
Zool. Soc., 1869, p. 431, and 1870, p. 669; also “List” of the animals of Zool. Soc. 1883, p. 192, fig. 35, 
and p. 193, fig. 36). The differences between these two, external and internal, are not great, but are 
worthy of note. 
