150 
Records of the Geological Haney of India. [vol. ix. 
b °[ J be h “ d “ half of a ri S ht ot «>e mandible (No. 215) brought 
by Mr. W. T. Blanford from the Irrawadi valley are as follows 
Length of three molars 
Length of last molar 
Width of ditto 
Length of second molar 
Depth at middle of last molar 
Ditto at second molar 
In. 
3 25 
1*6 
0*8 
10 
1*8 
2-0 
Other specimens from the Potwar country present similar dimensions to the above 
These dimensions are smaller than those of the first specimen, the jaw being of a more slen¬ 
der type; the teeth, however, in the two are of the same size. Falconer conjectured that 
there were two varieties, major and minor. I think, however, it is more probable that the 
slighter jaws (and crania) belonged to female individuals and not to a distinct variety. 
... .^f'~ rrhe ° Ml f P0r f a 0f the vertebral co,ul »" of Merycopotamus which I can iden- 
oL’Vo T Ve '' t a ’ ) W6 W tm> 8 P e ™ s iu the Indian Museum (Nos, 
1(,.18-39). These specimens only show the centrum, and portions of the pedicles, the neural 
arch being in both cases destroyed. The centrum has a broad and conical odontoid process 
laterally continuous with the articular facets for the atlas; the centrum is longer than broad'■ 
the inferior borders of the articular facets for the atlas form an almost continuous arch across 
tlio anterior extremity; there is a prominent straight keel along the inferior surface of the 
centrum; the inferior bar of the transverse process is long, and takes its origin about half¬ 
way up the vertebra ; it is separated by a smooth space from the articular facet for the atlas 
and is directed backwards and outwards; of the superior bar of the transverse process only 
the base ,s shown m our specimens; this is very wide and situated on the pedicle of the arch a 
little higher than the floor of the neural canal; the transverse process is perforated for the 
vertebral-artery. The exterior extremity of the pedicle is perforated tor the upper branch of 
the spinal nerve. The posterior surface of the centrum is slightly hollow, wider than deep, 
with a horizontal upper border, and a curved inferior border. 
The vertebra is at once distinguished from that of either the Pig or Hippopotamus by 
its much greater length in proportion to its breadth : in both the former animals the width 
of the posterior surface of the centrum is equal to two-tlurds of the total length of the 
\ i- e-a; whereas in Merycopotamus the width of the corresponding surface is less than half 
the total length of‘ the vertebra. 
Comparisons —The axis vertebra of the three genera have tho following points in 
common : the transverse process is perforated by the vertebrarterial canal, and the pedicle by 
the foramen for the spinal nerve; the odontoid process is bluntly conical, the inferior surface 
of the centrum keeled, and the inferior bar of tho transverse process is separated by a smooth 
surface from, the articular facet for the atlas. The axis of Merycopotamus is distinguished 
from that of Sus (besides the difference of length) by the rim connecting the inferior borders 
ol the facets for the atlas being less distinctly continuous below the odontoid process ; by the 
odontoid process being wider and flatter ; and by (in consequence of the greater length of the 
vertebra) the transverse process being much wider, and consequently the vertebrarterial 
canal much longer. It is distinguished from the axis of Hippopotamus by its greater 
proportionate length and the lesser development of the rim connecting the facets for the 
atlas; the transverse process is also slightly wider. 
