492 MR. R. LYDEKKER ON SCELIDOTHERIUM. [Nov. 16, 
new species, for which they proposed the name of S. 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 S. 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 Sefior Ameghino* has applied the new name 
of Scelidotherium? 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 S. lep- 
tocephalum and S. tarijense ; S. capellini, however, as being founded 
on a specimen which has not yet been figured, must be regarded 
merely as a nominal species ; while S. minutum, Lund, is apparently 
founded upon immature specimens, and S. dellulum upon a single 
unfigured tooth. With regard to S. buchklandi and S. 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 Platyonyz, the only 
one that can be regarded as satisfactory is P. brongniarti, which is 
founded on a nearly complete skull. P. euvieri is founded on a 
fragment of a mandible which does not afford more satisfactory 
characters than the one on which S. buchlandi 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 S. 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 Rendus, vol. ci. p. 1291 (1885). 
2 Bol. Ac, Nac. Cordoba, vol. ix. p. 184 (1886). 
3 In P. Gervais’s ‘Zool. et Pal. Générales,’ sér. i. p. 1382 (1867-69). 
