AESINOITHEEIUM ZITTELI. 69 



C. 8288. Symphysis and front of rami of a young mandible about the same age as last, and 

 with the same teeth in situ. The lengths of the teeth are : mm. 3, 2'8 cm. ; mm. 4, 

 3'3 cm.; m. 1, 3"8 cm. The symphysis extends to beneath the front of mm. 4 ; its length 

 is about 8 cm. 



M. 8822. Fragment of right ramus of mandible with mm. 3 and portions of mm. 4 in situ ; mm. 2 is 

 represented by its broken roots, and in front of it the crown of pm. 1 is just appearing. 

 This tooth is placed very obliquely in the jaw, and must gradually rotate into its 

 normal position as the growth of the mandible allows it room to do so. 



Presented hy the Egyptian Government, 1904. 



M. 8823. Anterior portion of right ramus of very young individual similar to M. 8822. In this 

 also the crown oi pm. 1 is just appearing, and is here placed almost transversely. In 

 front of it are the alveoli of the canine and three incisors. Behind is the broken base 

 of mm. 2. The symphysis extended back as far as the posterior end of mm. 2, and the 

 mental foramen is beneath the anterior column of the same tooth. 



Presented by the Egyptian Government, 1904. 



M. 8410. Left upper molars. 



M. 8825. Nearly unworn upper m. 3. Presented ly the Egyptian Government, 1904. 



C. 8942. Upper m. 3 slightly worn. 



C. 8943. Upper m. 2 with inner wall just formed, showing the roots. 



M. 8382. Right upper molar, much worn, showing roots. 



Presented hy the Egyptian Government, 1902. 

 111.8804 a. Right upper molar, much worn, showing roots. Figured on PI. V. figs. 8, 8 A. 



Presented by the Egyptian Government, 1904. 



M. 8804. Right upper molar, rather less worn than last. Figured on PI. V. fig. 7. This specimen 

 and the last are very large, and may belong to Arsinoitherium andrewsi. 



Presented by the Egyptian Government, 1904. 

 C. 9236. Two well-pres.erved right upper molars. 



C. 8291. Two upper molars considerably smaller than usual, possibly indicating the existence of a 

 smaller species. 



C. 7921. Right upper premolar. 



Dimensions (in centimetres) of skulls of Arsinoitherium zitteli : — 



1. 2. 3 (type). 4. 5. 



0.8128. M.8463. C.8130. C.7805. M.8800. 



Length from condyles to tip of snout 80 77 74 .... 65'5 



hom 109-4 100 78-4 73-4 64 



„ „ „ small horn ... 42 38 38-9 36 32-7 



"Width of roof at narrowest (between temporal fosssB) 11'4 13 9'7 10-4 12 



„ at zygomatic arch 35-6 33-5 31-6 28-3 31 app. 



Greatest width of occipital surface 25-7 app. 26 app. 24-6 21 20 



„ ,, between tips of small horns . . . 25'4 app. 24-5 23'2 17'1 17 app. 

 J, „ of the combined bases of the large 



horns 24-5 27 24-6 21 16-8 



,, of each horn at base (antero- 

 posterior) . 18 22 15-2 14 app. 13-4 



