ON MIOCENE PROBOSCIDIA FROM BALUCHISTAN. 609 



31. Miocene Probosciclia from Balucliistau. By C. Foester 

 Cooper, M.A., F.Z.S., Superintendent of the University 

 Museum of Zoology, Cambridge. 



[Received May 3, 1922 : Read May 23, 1922.] 

 (Plates I.-IY.* and Text-figures 1-12.) 



The present paper contains a description of some Proboscidian 

 I'emains obtained during two expeditious to the Lower Miocene 

 deposits of DeraBugti in Baluchistan. 



These fragments are of interest, as they throw some further 

 light on the earliest known Indian Elephants which have been 

 described partly as a variety of Bxinolophbdon angustidens t and 

 partly as belonging to a genus, Hemimastodon $, not known else- 

 where. There are also teeth and a fragment of a lower jaw of 

 a small Dinotherium. 



Schlesinger §, in his beautifully illustrated account of the 

 Mastodons in the Natural History Museum of Vienna, has figured 

 and described two forms of B. angustidens. The criteria for 

 distinguishing these two vai'ieties lie, according to him, in the 

 structure of the molars, and his description seems to refer 

 especially to the intermediate teeth as being the more commonly 

 found remains. In both forms the ridges consist of a large 

 round outer cusp on the outer side of the tooth, with a smaller 

 cusp pressed against its inner border and with one or more 

 additional cusps in the valleys which separate the ridges. On the 

 inner side of the tooth the ridge is continued by two similar 

 main cusps — a larger on the outer side of the tooth and a smaller 

 on the median side, but without any accessory cusps in the 

 valleys. 



Of the two varieties, one, which Schlesinger calls var. typica, 

 shows these cusps as round in section and rather separate from 

 one another, the surface of wear of the cusps being circular and 

 flat with the genei-al surface of the tooth ; the other, var. suh- 

 tapiroidea, differs in having the cusps more elliptical in section 

 and less separate from one another, the accessor}^ columns are 

 less developed, and the areas of wear are oval and their planes 

 slope from the general level of the tooth. While making these 

 distinctions, Schlesinger at the same time denies the validity of 



* For explanation of the Plates, see page 626. 



t Lydekker, 'Palseontologia Indica,' ser. 10,. vol. vii. ,pt. 4, pp. 23'-25 (1884). 

 I use this generic name after Schlesinger, with whose work the chief comparisons in 

 this paper are made and without prejudice to otlier names. The British Museum 

 uses the name Tetrahelodon. My friend Professor H. F. Osborn writes to me since 

 this paper was set up in type that he prefers the name Trilophodon. 



X Pilgrim, ' Palaeontologia Indica,' n. s. vol. iv.pt. 2, p. 17 (1912). 



§ Schlesinger, Mitt. Geol. Geselt. Wien, Bd. xi. p. 133 (1918). 



