61 
TERTIARY VERTEBRATA OF THE FATtM. 
Arsinoitherium zitteli, Beadnell. 
[Frontispiece ; Plates I.-V. ; text-figs. 1-37.] 
11)02. Arsinoitherium zitteli, H. J. L. Beadnell, op. cit. pis. i.-v. 
1903. ,, „ fig.s. of skull, Geol. Mag. [4] vol. x. pis. xxiii., xxiv. 
1904. „ „ (J. W. Andrews, Geol. Mag. [5] vol. i. p. 157. 
Type Specimen. — Skull, three-parts grown, probably of male (PI. 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 all 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 
(PI. 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. & Loc. — Fluvio-marine beds (Upper Eocene) : north and north-west of 
Birket-el-Qurun. 
C. 8130 *. Skull of a three-parts-grown animal : the type specimen figured by Beadnell in ‘ A 
Preliminary Note on Arsinoithei'ium 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. 09, 70. The age of the animal is indicated by (1) the rounded horn-tips, 
(2) absence o£ 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. 1., 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. JV. figs. 1, 1 a, 
and was found in actual contact with the skull : i. 1, i. 3, and jnn. 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. (19, 70. J^resented hj IP. K. de Winton, Es<]., 1903. 
* The numbers with C prefixed are those of specimens in the Geological Museum, Cairo ; numbers v\ ith 
any other letter indicate that the specimen is in the British Museum. 
