XIV INTEODPCTION". 



'No. 19949 agrees, however, in the character of its incisors with the 

 one referred by Burmeister ^ to T. jjlatensis, hut in having the canine 

 separated by a diastema from iTs resembles that of T. hurmeisteri ; 

 and accordingly Sir E. Owen's reference of all the specimens to 

 the type species has been followed. It may also be observed that 

 whereas Dr. Burmeister describes T. hurmeisteri as considerably 

 larger than T. platensis, JN'o. 49197 is much smaller than the type 

 of the latter. The comparison of a considerable series of specimens 

 is therefore required to determine whether the variation in the form 

 of the incisors of T. hurmeisteri is a character of more than indi- 

 vidual value. 



It had escaped notice that the molar of Rhinoceros anti- 

 quitatis figured in part iii. p. 93, as well as that of Mastodon 

 angustidens, No. M. 2900 (pt. iv. p. 35), are figured by Grew in 

 his ' Catalogue of the Earities of Gresham College,' pi. xix. (1761) ; 

 and it thus appears that both specimens were probably presented 

 to the Museum by the Council of the Eoyal Society. The mandible 

 of Hipparion gracile, No. 248 (pt. iii. p. 53), is figured by Kaup in 

 the ' Nova Acta Ac. Cses. Leop.-Car.' vol. xvii. pi. xii. b. fig. 3. The 

 distribution of the Indian Pliocene and Pleistocene Elephants to the 

 eastward has been more fully worked out by Prof. K. Martin ^ since 

 the publication of pt. iv. In this memoir E. bomhifrons, E. clifti, 

 E. namadicus, and E. hysudricus are recorded definitely from Java ; 

 while the name E. {Stegodon) trigonocephalus is applied to two crania, 

 from the same island, with a dentition of the type of that of E. in- 

 signis, and it is suggested that the Javan specimens noticed in pt. iv. 

 p. 90 may belong to the same form rather than to E. insignis. The 

 Indian Sus hysudricus is also recorded from the same region. 



Whenever practicable the references to the authorities for the 

 generic and specific names have been verified after they were in 

 type, and I have much pleasure in expressing my debt to Mr. B. B. 

 Woodward for his aid in this respect. I am also indebted to Mr. 

 0. Thomas for much valuable assistance and advice in regard to tlie 

 classification and nomenclature of the Marsupialia, and I may 

 observe that it was only after full consultation with him that the 

 generic terms Triacanthodon, Peraspalaoc, and probably Peralestes 

 were velegatcd to the rank of synonyms. Mr. W. Davies has again 



^ An. Mus. Buenos Aires, vol. pis. ix.-xi. T. Oweni, Burmeisteiv is appar-' 

 ently identical with the typical T. platensis. 



'^ " Beitr. Geol. Ost-Asiens u. Austral," Samral. geol. Eeichs-Mus. Leiden, 

 vol iv. pt. 2 (1887). 



