98 Records of the Geoloylcat Survey of India. [vol. xr. 
M'e should expect that the upper incisors were likewise of unusual size in 
R. planidens, and such appears to have been the case. Prom the district where 
the upper molars and lower jaw of R. planidens were obtained, Mr. Theobald has 
obtained two upper incisors of a Rhinoceros of gigantic size, which I have no 
doubt belonged to the same species ; the length of one of these specimens is up¬ 
wards of d'd inches, its thickness T5 inch, and the height of its crown 1'9 
inch. 9’he lapper incisors of the other Siwalik species of Rhrnoceros are not 
known ; the present specimen is, however, far too large to have belonged to R. 
sivalensis or R. palatindicus, while R. platyrhimis is not known to occur in the 
Punjab, and if we may judge from Colonel Baker’s cranium of this species seems 
not to have had permanent upper incisors. 
The above comparisons point most clearly to the speciiic distinctness of the 
gigantic fossil Rhinoceros of the Punjab; in its upper molars this species approaches 
nearest to R. sivalensLs, but is distinguished by their larger size and their 
bold cingulum and tubercle in the median valley; in the number of its lower 
incisors the new .species agrees with R. palcemdicus, but is distinguished by 
their curvt'd form and much greater size. 
Genus: Listeiodon. 
Of this genus, which has still an ineerta sedes, Mr. Theobald has obtained an 
upper molar of a very small species quite distinct either from the Indian L. 
pentapotamiai or the European L. splendens, or L. lartetU, and which must be re¬ 
ferred to a new species. The specimen was obtained from the Siwaliks of the 
village of Jabi in the Punjab, and will be described and figured on a fitture 
occasion; I propose to call the species after its discoverer, L. theohaldi. 
RODENTIA. 
Genus: Hysteix. 
At page 706 of the fourth volume of the “Journal of the Asiatic Society of 
Bengal,” in a list of Siwalik fossils given by Falconer and Cautley, there 
occurs the narue of the genus Hydrix, as having been obtained with the other 
specimens. The name of the genus again appears on page 293 of the fifth 
volume of the same Journal, and also in the Introduction to the “ Fauna Antiqua 
Sivalensis” (Pal. Mem., Vol. I,p. 23). I canfind, however, no further mention of 
the genus in Falconer’s papers, nor any notice of the specimen on which the 
determination was made ; this specimen (or specimens) has, in all probability, been 
lost. 
With the exception of the occurrence of the name in the above lists, we have 
hitherto known nothing of the occurrence of Hydrix in the Siwaliks; towards the 
end of last year, however, Mr. Theobald forwarded to the Indian Museum a portion 
of the mandible of a species of this genus, obtained from the Siwaliks of the 
village of Asnot, which forms the object of the present preliminary notice. 
The specimen consists of the middle portion of the i-ight ramus of the mandible 
containing the two first molars, and the sockets of the last premolar and last 
molar; the cutting extremity of the incisor of the same side was also obtained. 
