64 TEETIAET VEETEBEATA OF THE FATtM. 



Arsinoitherium zitteli, Beadnell. 



[Frontispiece ; Plates I.-V. ; text-figs. 1-37.] 



1902. Arsinoitherium sitteli, H. J. L. Beadnell, op. cit. pis. i.-v. 



1903. ,, „ figs, of skull, Geol. Mag. [4] vol. x. pis. xxiii., xxiv. 



1904. „ „ C. W. Andrews, Geol. Mag. [5] vol. i. p. 157. 



Ti/pe Specimen. — Skull, three-parts grown, probably of male (PL III. figs. 1, 1 a) ; 

 Geological Museum, Cairo. 



The type species, with mandible attaining a length of about 55 cm. ; the length of 

 the three upper posterior premolars and the molars together about 25'5 cm. 



This is a species of very variable proportions, known by several skulls and 

 numerous other parts of the skeleton, nearly aU found isolated. Its remains are 

 only distinguishable from those of the larger species, A. andrewsi, by their size, and 

 it is possible that some of the specimens catalogued here {e.g. the pelvis no. C. 8413) 

 may really belong to the latter form. Among the adult skulls there are two 

 types distinguished by the form of the great nasal horns, namely, (i) those in which 

 the horns are very large, trihedral, and sharply pointed, probably referable to males 

 (PL I.) ; and (ii) those in which the horns are much shorter, somewhat rounded, and 

 irregularly ossified at their tips, probably referable to females (Beadnell, op. cit. 

 pis. iii., v.). 



Form. & Log. — Fluvio-marine beds (Upper Eocene) : north and north-west of 

 Birket-el-Qurun. 



C. 8130 *- Skull of a three-parts-grown aninaal : the type specimen figured by Beadnell in ' A 

 Preliminary l^ote on Arsinoitherium zitteli, Beadn., from the Upper Eocene Strata of 

 Egypt,' pis. i., ii., vi. (Cairo, 1902) ; also on PI. III. figs. 1, 1 a. The dimensions are 

 given on pp. 69, 70. The age of the animal is indicated by (1) the rounded horn-tips, 

 (2) absence of prenasal bar, (3) anterior lobe of m. 3 only just coming into wear. 



M. 8463 *. Skull and mandible together with a rib of an adult animal, probably a male. The skull 

 is figured in the Geol. Mag.. [4] vol. x. pis. xxiii., xxiv., also on Pis. I., II., with the 

 ends of the horns and part of the right side of the skull restored in plaster, the restored 

 portions being indicated by dotted lines : i. 1, i. 3, c, and "pm. 1 are wanting on both sides; 

 the last molar is moderately worn. The mandible is figured on PI. IV. figs. 1 1 A, 

 and was found in actual contact with the skull : i. 1, i. 3, and pm. 1 are wanting on 

 the left side, i. 1, i. 2, i. 3, c, and pm. 1 on the right. The dimensions of this skull and 

 mandible are given on pp. 69, 70. Presented ly W. E. de Winton, Esq., 1903. 



* The numbers with C prefixed are those of specimens in the Geological Museum, Cairo ; numbers with 

 any other letter indicate that the specimen is in the British Museum. 



