492 MR. R. LYDEKKER ON SCELIDOTHERIUM. [NoV. 16, 



new species, for which they proposed the name of 8. capellini, on the 

 evidence of a lower jaw from the Pleistocene of Buenos Ayres. In 

 1881 Dr. Burmeister published in the Monatsb. k. preuss. Ak. Wiss. 

 (pp. 374-380) a description with figures of the manus, pes, and 

 knee-joint of a skeleton of Scelidotherium from the Pleistocene of 

 the Argentine Republic, which was referred to 8, leptocephalum. 

 In 1885 Dr. Fischer^ described a skeleton lately acquired by the 

 Paris Museum of Natural History, which he refers to S. leptoce- 

 phalum ; while in 1886 Seiior Ameghino" has applied the new name 

 of Scelidotheriumi bellulum to a single tooth from Parana. Finally 

 it may be observed that the so-called Scelidotherium ankilosopum, 

 Bravard^ is the same as Mylodon {Grypotherium) darwini, Owen. 

 Other memoirs of minor import, which need not be quoted here, have 

 also been published. 



It will be seen from the above that no less than eleven specific 

 names have been applied to animals of this group ; six of which are 

 included by Messrs. Gervais and Ameghino, in the memoir cited, in 

 Scelidotherium, while four are referred to Platyonyx, the eleventh 

 being of later date. Among the seven included under the former 

 genus, there is no difficulty in regard to accepting the typical 8. lep- 

 tocephalum and 8. tarijense ; 8. cajiellini, however, as being founded 

 on a specimen which has not yet been figured, must be regarded 

 merely as a nominal species ; while 8. minutum, Lund, is apparently 

 founded upon immature specimens, and 8. bellulum upon a single 

 unfigured tooth. With regard to 8. bucklandi and 8. oweni of 

 Lund, the type specimens are so imperfect that they do not appear 

 to me to afford characters of sufficient importance to enable other 

 specimens to be identified with them ; and I have therefore been 

 compelled to ignore these names when considering the affinities 

 of the specimens described below. Of the four so-called species 

 ranged by Messrs. Gervais and Ameghino under Platyonyx, the only 

 one that can be regarded as satisfactory is P. brongniarti, which is 

 founded on a nearly complete skull. P. cuvieri is founded on a 

 fragment of a mandible which does not afford more satisfactory 

 characters than the one on which 8. bucklandi is founded ; while 

 P. blainvillei and P. agassizi have been named on still more 

 unsatisfactory evidence, and must certainly therefore be regarded as 

 not of more than nominal value. 



The object of the present communication is, first, to show that 

 one of the specimens figured by Sir Richard Owen in the memoir 

 in the ' Philosophical Transactions,' already cited, does not belong 

 to 8. leptocephalum, which also leads to the conclusion that the 

 specimen described by Dr. Burmeister in his second memoir under 

 the same name is likewise distinct ; and, secondly, to describe a skull 

 belonging to a series of specimens, from the Pleistocene of Chili, 

 recently acquired by the British Museum. In the course of this 

 paper it will be shown that there appears no reason for the retention 



1 Comptes Eendus, vol. ci. p. 1291 (1885). 



2 Bol. Ac. Nac. Cordoba, vol. ix. p. 184 (1886). 



3 In P. Gervais's 'Zool. et Pal. G6n6rales,' s6r. i. p. 132 (1867-69). 



