42—8 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
Species 2 : Hippopotamus irayaticus, Falc. and Cant. 
Syn. Ilexaprotodon iravaticus^'Y . and C. 
Bistonj . — In plate LVII., figs. 11, 11a, 10, 10a, 10b, 10c, of the ‘H^bA.S.” 
there are figured two specimens of the symphysis of a small hexaprotodont 
hippopotamus, under the name of II. iravaticus ; the first specimen^ being nearly 
complete. In plate LXXXIII., fig. 12, of the same work, the lower end of a small 
radius is figured under the same name : and in Falconer’s “ Catalogue of the 
Fossils of the Asiatic Society of Bengal” the lower ends of a radius, and a femur 
are referred to the same species.^ All these specimens cajne from Burma. With the 
exception of a note published in tlie “ Palseontological Memoirs,”® in which it is 
stated that “ II. iravaticus is a size larger than II. liheriensis^'' this is the Avhole of the 
information left by Falconer in regard to this species. In 1882 a note on this 
species was published by the present AAuiter,'* Avherein it Avas suggested that a 
mandible from the Punjab might perhaps be referred to it : subsequent comparisons 
have, howeA^er, indicated that this specimen, as already mentioned, belongs to H. 
sivalensis. 
Mandible. — The type mandible, to wliich the reference has lieen already given, 
is a sub-adult specimen, with pm. 2 half protruded. It is distinguished from the 
mandible of H. sivalensis by its inferior size, projiortionately longer symphysis, 
laterally compressed i. 3, as Avell as by the circumstance that the six incisors, instead 
of forming a straight line betAveen the canines,® are placed irregularly ; the second 
being above the first, and the third beloAv both the others. The alveoli of the three 
first premolars also shoAV that pm. I and pm. z Avere separated by proportionately 
longer intervals.® The more important of these diflterences are exhibited by the 
following measurements, viz. : — 
H. iravaticus. 
H. sivalensis. 7 
Length of symphysis .... 
5-1 
7-1 
Interval between canines 
4'45 
80 
Depth at pm. 1 
2-9 
4-6 
Longer diameter of canine 
1-48 
2-4 
These differences are of such importance as to leave little doubt of the specific 
distinctness of the small IraAvadi hippopotamus® from II. sivalensis. The only other 
described species with Avhich the former could be identical Avould be the subsequently 
named H. hipponensis ; but the knoAAm remains of that species do not permit of exact 
comparison with H. iravaticus. 
The extremely long mandibular symphysis of the latter, and the relatirmly 
1 B. M., No. 14,771. 2 Vide “Pal. Mem.,” vol. I., p. 142. s A"ol. II., p. 406. 
4 ‘Records,’ vol. XA^., p. 31. 5 Compare “ F.A.S.,” pi. LXII , fig. 4. . 6 Ibid, pi. LXI., figs. 4, 5. 
7 Ibid, pi, LXI., fig. 5 (B. M., No. 17,085). 
8 There are several specimens of the symphysis of the mandible of small hippopotami from Burma in the collection of 
the Indian Museum {e.g. No. B. 304), which may very probably belong to the present species. The present writer’s attention 
was not directed to the specific characters of these specimens during his service on the Cieological Survey. 
