INTRODUCTION. Xlll 



mentioned that Oastoroides (pt. i. p. 221) is regarded by Coues and 

 Allen ^ as forming the type of a distinct family, which is placed in 

 the Hystricomorpha. Alston's identification of Arvicoila amhiguus 

 (pt. i. p. 231) with Myocles (or Cuniculus) torquatus had escaped 

 notice, and the specimens are therefore re-entered under the latter 

 name in the Supplement. Among the Artiodactyla the type crania 

 of the Siwalik Antelopes referred in pt. ii. to Strepsicei-os^ Hippo- 

 tragus, Gobus, and Alcelaphus, have been figured in the ' Palaeonto- 

 logia Indica,' ser. 10, vol. iv. pis. ii.-iv. (1886) ; and Alcelaphus 

 hakeri (pt. ii. p. b^) has been found to be identical with A. paJce- 

 indicus '^. Metri other ium, incidentally mentioned in part ii. p. 60, 

 more probably belongs to the Anoplotheriidce. Ccenotlierium quin- 

 quedentatum (pt. ii. p. 175) is regarded by Dr. Schlosser^ as identical 

 with G. courtoisi, Gervais, which was incorrectly referred by Kowa- 

 levsky * to Hyopotamus. The specimen provisionally referred in the 

 second part (p. 182) to Xiphodo7i gelyensis is made the type of anew 

 species in the Supplement, since Dr. Schlosser ^ has shown that the 

 so-called X. gelyensis does not belong to Xiphodon. The same 

 writer suggests^ that Diplopus (pt. ii. p. 216) is identical with 

 Dichodon, but the bones of the former appear decidedly too large for 

 the one known species of that genus. In the genus Merycopotamus, 

 since the publication of pt. ii., the following specimens, viz. M. dis- 

 similis (p. 209), J^os. 18441, 18442, and M. nanus (p. 21?), IS'os. 

 16551, 18407, and 153409, have been figured by the writer in the 

 ' Palaeontologia Indica,' ser. 10, vol. iv. pis. v., vi. In the Perisso- 

 dactyla, the North- American forms originally referred by Prof. 

 Cope to Pachynolophus (pt. iii. p. 13) have been made the types of 

 the genus Heptodon, Cope'^. In the Toxodontia it has been 

 mentioned by Messrs. Gervais and Ameghino ^ that the cranium of 

 Toxodon, No. 49197 (pt. iii. p. 168), in having the first pair of 

 incisors larger than the second, diff'ers from the type specimen of 

 T. platensis, and agrees with that known as T. hurmeisteri, Giebel ^ ; 

 and the same feature is also shown in No. 19948. The mandible 



^ " Monogr. North American Rodeutia," Rep. U.S. Greol. Surv. Terrs, p. 419 

 (1877). 



^ PalaBontologia Indica, op. cit. p. 14. 



3 Op. cit. p. 54. * Phil. Trans. 1873, p. 25. 



5 Op. cit. p. 297. ' Ibid. p. 298. 



"^ See " Yertebrata of the Tertiaries of the West," Rep. U.S. Geol. Surv. Terrs, 

 vol. iii., Book i. p. 653 (1884). 



^ Mammiferes Fossiles de I'Amerique Meridionale, p. 83 (1880). 



8 Zeitschr. ges. Naturwis. vol. xxviii. p. 134 (186G). 



