386 E. T. Newton — The Great Beaver in the Thames Valley. 



described a remarkably fine skull of T. Cuvieri, whicb had been 

 obtained by Mr. A. Savin from the 'Forest Bed' of East Eunton, 

 and is now in the British Museum. The skull named by M. Laugel 

 Gonodontes Boisvillettii,^ which is believed to be TrogontJierium 

 Cuvieri, was obtained from a bed at St. Prest, which is of about 

 the same age as the ' Cromer Forest Bed.' The stratigraphical 

 position of the deposit at the Sea of Azof, which yielded the original 

 TrogontJierium Cumeri, still remains uncertain. 



The above sketch will give an idea of our knowledge of Trogon- 

 tJierium ten years ago, and no addition seems to have been since 

 made to the history of this interesting rodent. I am now, however, 

 able to record its occurrence in a deposit of Pleistocene age in the 

 lower part of the Thames Valley. In May of the year 1900 

 Mr. PL Stopes^ gave an account before the Anthropological Institute 

 of a bed of gravel (at 78 feet O.D.) on the west shoulder of the Ingress 

 Valley, near Greenhithe, Kent, which is remarkable for containing 

 great numbers of Neritina fluvintilis, together with many other 

 species of mollusca and vertebrata. The extinct forms included 

 among these fossils showed the deposit to be of Pleistocene age. 

 Mr. Stopes has been careful to preserve all the mammalian remains 

 he could obtain from this bed, but other workers have not been 

 unmindful of the importance of this discovery, and, as may be 

 gathered from Mr. Stopes' paper, they have secured some most 

 interesting specimens. Mr. A. S. Kennard has made a large col- 

 lection of the mollusca, and Mr. M. A. C. Hinton has obtained many 

 vertebrate remains, chiefly the small forms included in Mr, Stopes' 

 revised list. Another important series of bones has been secured 

 by that assiduous worker Mr. W. J. Lewis Abbott, most of whose 

 specimens are of species included in the published list, but there is 

 one large rodent incisor (Fig. 1) which Mr. Abbott suspected from 

 its size and shape might be TrogontJierium. A rumour of this 

 ' Great Beaver ' from the ' Neritina ' deposit seems to have been 

 the cause of Castor sp. appearing in Mr. Stopes' list. 



This incisor tooth was sent to me some twelve months ago, but 

 I have delayed publishing an account of it, hoping that additional 

 material would be forthcoming. The specimen (Fig. 1) is a lower 

 incisor tooth, as shown by the large diameter of its curve in pro- 

 portion to its thickness ; it measures along the outer curve 132 mm., 

 but is imperfect at both ends. The curve of the tooth, if completed, 

 would form a circle with a diameter of about 150 mm. In cross 

 section (Fig. 2) the tooth is pear-shaped ; its width being 11 mm., 

 and from front to back about 13 mm. The front is rounded and 

 the hinder part has been angular, but this edge is nowhere quite 

 perfect. The portion of the front of the tooth, which is covered by 

 enamel, is shown in Fig. 2 by the thick dark part of this outline 

 of the cross section. The inner edge of the enamel is slightly 



> Bull. Soc. Geol. France, 1862, ser. ii, vol. xix, p. 709. 



2 Journ. Anthr. Inst., vol. xxix, p. 302. This paper was reprinted in 1901 with 

 a greatly extended list of fossils — 67 species. 



