154 
Records of lire Geological Survey of India. 
[VOL. IX. 
Addenda and Corrigenda to Paper on Tertiary Mammalia [ante page 86) 
by R, Lydekker, B.A., Geological Survey of India. 
Hydaspidothf.rium meg acbph alum, nov. gen. nobis.—Tlie cranium from the Siwaliks 
referred to in the last number ot' the Records under the name of Jiramatherium, has now 
been cleaned from matrix, and turns out to belong to n new genus of Sivalherida ?, for which 
I propose the name tfy&tiapidotherium, from the classical name of the river Jhelum, near 
Which it was found. The distinctive characters of the cranium are the possession of one 
common horn-base on the vertex, and the absence of anterior horns ; the profile is concave, 
the orbit depressed, and separated by a long interval from the horn-core 5 the teeth resemble 
those of Branutlherivm. A figure and full description will subsequently appear. 
The genus TJrsi.ta.Tus (Hodgson’s synonym for MelUvora) should be removed from the 
lists of extinct genera, p. 95, and added to the lists of genera common to the Indian Tertia- 
ries. and to the living fauna; of India and Africa. The genus Sanithcriuin —H. von Meyer— 
{Sits pusillus, Falc.) should be added under Artiodactyla to the lists from which Ursitaxus 
is removed. 
Occurrence of Plesiosaurus in India, by R. Lydekker, b.a., Geological Survey of 
India. 
The discovery of the remains of this genus in the Oolite of Kachh is the first instance 
recorded of its occurrence in India. The specimen on which this determination is founded 
is a portion of the distal extremity of a mandible; it was discovered by Mr. Wynne at Bui- 
l'ooria-in Kachh, in the Umia (Titkonian and Portlandian) beds; it comprises the whole of 
the symphysis and small portions of tire rami of the mandible ; on the right side it contains 
the alveoli of five teeth, and on the left side of four. The alveoli are completely surrounded 
by bone; the distal extremity of tlio symphysis is rounded, its upper surface flat, and pierced 
by neural foramina, interiorly to the teeth ; there is an ovate prominence on the upper sur¬ 
face at the junction of the rami, the inferior surface is rounded and convex, the symphysis 
being rather longer here than on the upper surface. The dimensions of this specimen are as 
follows :— 
In. 
Length of symphysis on tipper surface ... ... ... ... 292 
Ditro ditto lower surface ... ... ... ... 3’55 
Width of jaw at union of rami ... ... ... ... ... 3'50 
Width of jaw at second alveoli ... ... ... ... ... 2'61 
Thickuess of jaw at union of rami ... ... ... ... T95 
The specimen agrees almost exactly in form and size with the lower jaw of Plesiosaurus 
dolichodeirus of the English Lias; hut it would not be prudent to affirm its identity till 
further specimens are discovered. The range of the genus in England is from the lower 
Lias to the lower Cretaceous, so that no inferences can he drawn from this specimen as to the 
homotaxis of the beds from which it is derived. 
