ON CHALICOTHEROIDKA FROM BALUCHISTAN. 357 



19. (Hitilicotheroidea iVoin Balucliistiiu, By C FoKiSTER- 

 (JoOPER, M.A., F.Z.S., Su[)eriiitenilent of tlie Uiii- 

 versit}' Miisemn of Zoology, Ciunbridge. 



[Received April 16, 1920: Road May 11, 1920.] 

 (Plate I.* and Text-%uves 1 -7.) 



I)i'. Pilgrim, in his report t on the fossil vertebrate fauna of 

 the Bugti Hills, has described two forms of Ohalicotheres, of which 

 the smaller is represented by material too f ragmen taiy to be 

 named, while to tlie larger he lias given generic ra,nk with the 

 name of Phyllotillon naricus. 



My own collections have produced a sma,ll amount of further 

 material for study, fi'agmentai-y and in some cases much worn, 

 but sufficient to add in some points to our knowledge of these 

 two forms. 



Holland and Peterson % in their very complete memoir on 

 Jloropus elatas and the osteology oi tlie Olialicotheroidea. have 

 taken exception to the creation by Di'. Pilgrim of a separate 

 genus for his species, Phyllotillon naricus. This objection is 

 reasonable, seeing that the chief character on which the genus 

 is founded is one which occurs in other genera of Ohalicotheres. 

 Dr. Pilgrim states § that " the difference is particularly^ well 

 shown in the structure of the upper premolars. . . . An unworn 

 specimen of pm. 3 . . . . shows that the large inner cusp was 

 united to the ectoloph by a double instead of a single crest." 

 This statement, as Holland and Peterson point out, is ojaen to 

 alternative interpretations — viz., either that there is a crest 

 running from each side of the inner cusp to the ectoloph, or that 

 each crest is double. 



The former interpretation repi-esents tlie actual condition of 

 the tootli, and is the meaning Dr. Pilgrim wished to convey ||. As 

 this condition is found in Moi-ojrus it loses its value as a generic 

 character. On the other hand, to judge from Deperet's figure of 

 MaGVotheriani yrande ^, the fourth premolai- does appear to differ 

 in the arrangement of the crests from that of the Bugti specimens 

 in that the anterior ci'est seems less developed in M. grande, iu 

 which form the anterior external cusp is a separate rounded 

 hillock. Gaudry's figure of Schizotlieriimi vwdicum shows both 



* Fov explanation of the Plate, see p. 366. 



t Rec. Geol. Suvv. Ind. xl. p. 67, and Mem. Geol. Surv. Lid. n. s. vol. iv. Mem. 2, 

 p. 33. 



j: Mem. Canieo-ie Miis. vol. iii. no. 2, 1913. 



§ Mem. loc. cit. p. 33. 



II I had the opportiTiiitj' of consuliiiig Dr. Pilgrim on this point during a short 

 visit made bv him to Cambridge, and have his authority for niakiner this statement. 



«[ Arch, du Mus. d'Hist. Nat. de Lvon, xol. v. 1892, pi. iii. fig. 1. 



24* 



