216 RODENTIA. 



41450. The right innominate ; from the turbary of the Lea valley, 

 near Walthamstow. Purchased, 1869. 



39468 a. The scapula, the humerus, radius, and ulna of a young indi- 

 vidual; from the Fens of Lincolnshire. Purchased, 1865. 



Genus TROGONTHERIUM, Fischer 1 . 

 Syn. (?) Diobroticus, Pomel 2 . 



History. The genus Trogontherium was originally described by 

 Fischer on the evidence of a cranium from the Pleistocene of 

 Siberia. Eemains of a large Eodent from the Pleistocene of 

 England and France were subsequently referred by Owen 3 to the 

 same genus and species. P. Gervais 4 came, however, to the con- 

 clusion that both the English and French specimens were generically 

 distinct from Fischer's specimen, and adopted for them Pomel's 

 name of Diobroticus. This view is followed by Alston 5 and Flower" ; 

 but E. T. Newton 7 comes to the conclusion that Owen's view is 

 correct, alleging that the difference between Fischer's specimen and 

 the English and French form is merely due to differences in the 

 degree of wear of the cheek-teeth. As this view has not been dis- 

 proved, it is provisionally adopted here.* 



Trogontherium cuvieri, Fischer ". 

 Syn. (?) Diobroticus schmerlingi, Pomel 9 . 

 Castor trogontherium, Cuvier 10 . 



Hob. Europe. 



M. 472. Cast of the cranium, wanting the zygomatic arches and the 

 nasals. The original, which is Fischer's type specimen, 

 was obtained from the Pleistocene of Siberia, and is pre- 

 served in the Museum at Moscow. 



Presented by the Moscow University. 



M6m. Soc. Imp. Nat. Mosc. vol. ii. p. 260 (1809). 



Arch. Sci. Phys. Nat. vol. is. p. 167 (1848). 



Catalogue Foss. Eem. of Mammalia and Aves in Mus. Eoy. Coll. Surgeons, 

 p. 35(1845); British Foss. Mammals and Birds, p. 184(1846); Q-eol. Mag. 

 vo . vi. p. 49 (1869). 



Zool. et Pal. Generales, 1st ser. p. 81 (1867-69). 



Proc. Zool. Soc. 1876, p. 78. 



Catalogue of Mammalia in Mus. Eoy. Coll. Surg. p. 602 (1884). 



Geol. Mag. dec. 2, vol. viii. p. 256 (1881). 



Loc. cit. 9 Loc. cit. 



Ossemens Fossiles, 1st ed. vol. v. pt. 1. p. 59 (1823). The specific name 

 trogontherium has the priority over cuvieri ; but the former has been so gene, 

 rally used in a generic sense that it seems best to retain the latter. 



