40 MR. A. L. ADAMS ON THE OSTEOLOGY OF 
with none of the collines of the last milk-molar invaded. I can well believe, therefore, 
that fig. 4 belonged to a more advanced stage of growth in a much smaller Elephant. 
Moreover, from the alveoli being dong and narrow, it is also probable that the jaw 
would not have held the last of the milk-series of the largest form. The posterior 
portion of the ramus is not sufficiently entire to show whether or not the sulcus (I shall 
refer to it presently in the old jaw of the smallest form) was present; and the lower 
anterior portion is far too much injured to allow of comparisons. It would seem, how- 
ever, that, like the Asiatic, the dental foramen opened immediately under the condyle, 
as we shall see presently obtainsin the aged jaw, Pl. VI. fig. 1, which, like the one in 
question, is from Benghisa Gap, so fruitful in remains of the smallest form. 
4, The portion of a left ramus, No. 85 (Pl. VI. fig. 3), containing a fragment of a true 
molar of the smallest form, has unfortunately been injured at the part where a great 
amount of interest is centred. The jaw altogether is much mutilated. The cylindrical 
canal is partially preserved, and about 2 inches of the right ramus. The diasteme, 
however, is destroyed, and the ramus broken across in two places; and although it has 
been reunited, there is evidently some loss of substances, so that the distance between 
the alveolar border in front and the gutter is uncertain. What remains of the tooth 
comprehends the last six ridges. The alveolus, however, is entire; and at its front are 
the pits for the insertion of the two-pronged anterior fang, and behind them a single 
hole for the root of the fourth plate, as usually observed in penultimate and last true 
molars. Altogether the socket of the tooth gives a length of about 6 inches. The 
posterior talon is flat and concave, showing evident marks of pressure; whilst behind is 
a large cavity on the floor of which are traces of the dentine and fragments of enamel 
of agerm molar. All the ridges of the molar, excepting the last, were in wear. 
The following are the dimensions of the jaw :— 
The extreme length from the posterior margin of the ascending ramus to the edge of 
the symphysis is very little over 9 inches. This is allowing for a slight loss at the 
fracture near the latter. 
Length of the alveolar border, from the anterior margin of the ascending ramus to 
the diasteme, 4°8 inches. 
Height of the alveolar border at the outer edge of the ascending ramus 3 inches. 
Height of the alveolar border in front, near the diasteme, 3 inches. 
Transverse diameter at bulge of ramus, below the coronoid, 3 inches. The mandi- 
bular portion has much of the straight prolonged outline of the African ; and from what 
remains of the ascending ramus, its outline seems to have been much after the latter and 
figs. 1&4. The symphysial gutter is shallow, and the chin truncated, with only a very 
small rostrum. Most probably, from the fang-sockets in front of the alveolus, there was 
a fragment of the first true molar also in wear. As compared with Pl. VI. fig. 1, this 
jaw and its molar socket might fairly represent the second true molar of the smallest 
form in full wear. The measurements of the jaw accord well with that of an Asiatic 
