ON CHALICOTHEROIDEA FROM BALUCHISTAN. 



357 



19. Chiilicothcroidea irom Balucliistiin. By C. Forster- 

 (JoOPEU, M.A., F.Z.k^., Sa[)er"mteii!lent of the Uni- 

 versity Miisenm oi^ Zoology, Ciiiiibridge. 



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



(Plate I.* and Text-ti-ures 1 -7.) 



Pilgrim, in bis report t on the fossil vertebrate fauna of 

 the Bngti Hills, has described two forms of Chalicotheres, of which 

 the smallei' is represented by material too fragmentary to be 

 named, while to the larger he has given generic rank with the 

 name of PhyllotiUon naricus. 



My own collections have produced a, small amount of further 

 material for study, fragmentary 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 

 Moro2)i(,s elatas and the osteology of tlie Chalicotheroidea liave 

 taken exception to the creation l;)y Di-. Pilgrim of a, sepai-ate 

 genus for his species, Phyllotillon naricus. This objection is 

 reasonable, seeing that the chief character on which the genus 

 is founded is one wdiich occurs in other genera of Chalicotheres. 

 Dr. Pilgrim states § that " the dift'erence is particularl}^ well 

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

 specimen of pm. o , , . . shows that the large inner cusp was 

 united to the ectoloph b}^ a double instead of a single crest," 

 This statement, as Holiaiid and Peterson point out, is open 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 represents tlie actual condition of 

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

 this condition is found in Aforopus it loses its value as a genei-ic 

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

 MaGrotheinam grcmde%, the fourth premolar does ap^jear to difier 

 in the arra.ngement of the crests from tliat of the Bugti specimens 

 in that the anterior crest seems less developed in M. grande, in 

 which form the anterior exterufd cusp is a sepaiute i-ounded 

 hillock. Gau<lry's figure of Schizotherium modicum shows both 



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



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

 p. 33. 



X Mem. Canieo:ie Mus, vol. iii. no. 2, 1913. 

 .§ Mem, loc. cif. p. 33. 



Ij I had the opportunity of consulting Dr. Pilgriin on this point during a short 

 visit made hv him to Camhridge, and have his authoi-ity for making: this statement. 

 ^ Arch, du Mus. d'Hist. Nat. cfe Lyon, xol. v. 1892, ph iii. fig. 1. 



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