167—26 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
and tlie first and second true molars : the first true molar is considerably smaller 
than the second : the largest tooth is about half-an-inch in length, and four-and-a-half 
tenths in width. Each of the true molars carries four distinct columns, the summits 
of the inner pair forming complete crescents : there is a wide 1 cingulum 5 on the 
inner side. The external walls of the outer columns are more nearly perpendicular 
than in Merycopotamus , the angles of their bases less produced and the median ridges 
less developed. There is a more distinct loop connecting the external surfaces of 
these columns ; but this is flattened externally, and overlaps each column. 
There can be little, if any, doubt but that these teeth are generically distinct 
from Merycopotamus , though they probably belong to the same family. 
These teeth also present considerable resemblance to a tooth figured by Dr. 
W. Kowalevsky as belonging to a form intermediate between Byopotamus and 
Dichodon. 1 The latter tooth which has four lobes and a prominent connecting 
loop, has, however, a more truly ruminant structure, which is still more developed 
in Dichodon 2 itself. 
Genus III : HEMIMERYX, 3 n. gen. nobis. 
Species : Hemimeryx blanfordi. n. sp.: nobis. 
History. — Unsatisfactory as it is to form a new genus of animals merely on the 
evidence of a single tooth, still there are certain cases where there seems no satisfac- 
tory alternative but to adopt this proceeding ; and the present and following 
instances are cases in point. In both of these instances a single upper molar is before 
us, which cannot at present be identified with the molars of any described genus, and 
we have accordingly either to give these teeth new generic names, or to suffer the 
inconvenience of here and elsewhere alluding to them, without any distinctive title 
or means of identification. Under these circumstances the former alternative, as 
being the least objectionable of the two, has been adopted. 
In the “Records” for 1877, 4 an upper molar tooth obtained by Mr. W. T. 
Blanford from the lower Manclihars of Sind was briefly noticed, and considered to 
belong to a new genus of merycopotamid. In the following year 5 two other 
fragments of similar upper molars, and a lower molar considered as probably belonging 
to the same species (all obtained from the lower Manchhar rocks) were also noticed, 
and the generic term Hemimeryx was proposed for their receptioxi. The best of the 
above mentioned specimens are now for the first time figured, and are designated by 
the foregoing generic title, with the specific name of blanfordi , after the discoverer of 
the first specimen. 
Upper molar. — In figures 5 and 8, of plate XXIII. of this memoir, the original 
upper molar noticed above is represented. Figure 5 gives a view of the masticating 
surface, while in figure 8 the external aspect has been portrayed, but it unfortunately 
l ‘ Pliil. Traas.’ loc. cil., pi. XXXIX., fig. 15. 2 Owen, loc. cit., pi. IV., fig. 3. 3 From Hemi, half, and merux. 
i Vol. X., p. 7t>. 6 “ R. b. S. I.,” Vol. XI., ppi 79-80. 
