llYiENODON.— PTEKODON. 
219 
This genus is represented by a single specimen only, consisting of the anterior part 
of a right ramus of a mandible with the alveoli of the large canine and the anterior 
premolars, the roots of the latter being in situ. Associated with this, and no d-ouht 
belonging to the same jaw, is a tliird right lower molar. The crown of this tooth 
consists of two high secant cusps, which together form a cutting-blade : the posterior 
cusp is the larger and considerably the higher of the two. On the antero-external face 
of the anterior cusp near its base there is a small adherent tubercle ; there is no talon, 
though the cingulum is slightly developed on the posterior angle of the tooth. The 
outer face of the tooth is considerably worn, the direction of wear being such that the 
cutting-edge remains sharp. This tooth is similar in general form to the last lower 
molar of the European species of Ilycenodon, especially in the presence of the small 
antero-external tubercle and the absence of the talon ; the posterior cusp, however, is 
shorter and higher than in the other species. This specimen seems to be sufficient 
to show that remains of a Carnivore referable to the genus Ilycenodon or some closely 
allied type exist in these beds, though insufficient to justify the establishment of a new 
species. 
Form. & Log. — Fluvio-marine beds (Upper Eocene) : north of Birket-el-Qurun. 
C. 8812-3. Fragment of anterior part of right ramus of mandible and a last lower molar. The 
dimensions (in centimetres) of the tooth are : — Length 1'3, width ’7, height of posterior 
lobe IT. 
Genus PTERODON, de Blainville. 
[Ann. FranQ. et Etrang. d’Anat. et Phys. vol. iii. (1839) p. 23.] 
1885. Hemipsalodon *, Cope, Amer. Naturalist, vol. xix. p. 163. 
1887. P seudopterodon *, Schlosser, Beitr. Pal. u. Geol. Oesterreich-Ungarus u. d. Orients, vol. vi. 
p. 201; also vol. viii. (1890) p. 71. 
This genus has hitherto been recorded only from the Eocene of Europe. In the 
upper jaw the third molar is small and transversely elongated. The first and second 
molars have an antero-external cusp, wanting in Ilycenodon, and the posterior lobe of 
the cutting-blade is smaller. In the lower molars there is no postero-internal cusp, 
but there is a small cutting-talon. M. 3 is much the largest. The jaw is relatively 
short and heavy. 
Only one species at present known from Egypt. 
* Fide Matthew, Bull. Amer. Mus. Nat. Hist. vol. xiv. (1901) p. 20. 
