290 Prof. E. Ray Lankester — The Trilophodont Maatodon 



was shown to contrast with Mastodon Arvernensis, tbe teeth of which 

 occur at the base of both the Suffolk and Norfolk Crags in a peculiar 

 condition of mineralization, differing widely from that of the present 

 specimen and from that of some other fragments of Mastodon teeth 

 not referable to the species M. Arvernensis. The molars of 

 M. Arvernensis from the East Anglian area are very seldom water- 

 worn, and in many cases are found, not in the condition of ' enamel 

 crowns,' but with the softer material which forms the fangs of the 

 tooth still perfect. On the other hand, the teeth of Rhinoceros 

 Schleiermacheri, of Tapirns prisciis, of Hipparion, and some other 

 mammals, which occur in the same deposit, are in the same water- 

 worn condition and in the sam-e state ot mineralization as that which 

 characterizes this Trilophodont Mastodon and some other fragments 

 of Mastodon teeth referred by me to M. tapiroides. The conclusion 

 to which I came was, that we have at the base of the Suffolk Crag 

 successive sweepings (as it were) of the land surface, the latest 

 (Pliocene) being represented by M. Arvernensis and possibly some 

 other remains, an older sweeping by the Trilophodont Mastodon, 

 other Mastodon fragments, and the Rhinoceros, Hipparion, and 

 Tapirns, whilst a still older contribution is that of the Eocene land 

 fauna indicated by Coryphodon and Hyracotherium. 



The specific identification of the single penultimate Ti'ilophodont 

 molar was a difficult task, especially as the valleys were filled by 

 matrix. After discussing the possible identification of the tooth 

 with M. (Trilophodon) Borsoni, a Pliocene species, I came to the 

 conclusion that the probabilities were in favour of its being referable 

 to M. {Trilophodon) tapiroides (= turicensis. Pom.). 



The chief reason which I have had for making a re-examination 

 of this specimen is, that my main conclusion as to its nature has been 

 directly traversed in two separate publications by Mr. R. Lydekker, 

 F.R.S. I find that Mr. Lydekker had never examined the original 

 specimen, but based his opinion on a coloured cast which I had 

 presented to the British Museum. This cast did not show the under 

 surface of the specimen at all, and therefore was devoid of any 

 evidence which could justify the formation of an opinion as to the 

 completeness or incompleteness of the enamel crown. 



In a paper on Crag Vertebrata, Mr. Lydekker writes as follows 

 (in the Quart. Journ. Geol. Soc, vol. xlii, p. 365, 1886) : — "The 

 evidence for the presence of M. longirostris, Kaup, is afforded b}' 

 several fragments of molars in the British Museum,^ and by the 

 greater part of a second or third upper true molar - figured by 

 Lankester in vol. xxvi, pi. xxxiv, figs 1, 2, of the Society's Journal, 

 and regarded by him as the con)plete tooth of a Trilophodont species. 

 The examination of the cast of the latter shows, however, without 

 doubt, that it has lost one or more posterior ridges, and that, as 

 suggested by Lartet,-' it really belongs to M. longirostris, the form 



^ These and the preceding specimeas were notice! by Lydekker in past iv of the 

 British Museum Catilogue of Fossil Mammalia. 

 2 Cast in British Museum. 

 ^ See Lankester, op. cit., p. 508. 



