PODOCNEMIS FA.TUMEXSIS.— STEREOGENYS CROMEKf. 
295 
C.8790. 
Nearly coiiipleto shell, descrihoil above and 
ceiiliinetres) of this specimen are : — 
Length of carapace in middle line 
Approximate width of carapace 
Greatest length of plastron .... 
Width of anterior lobe of plastron 
Length of anterior lobe of plastron 
Whdth of posterior lobe of plastron . 
Length of posterior lobe of plastroti . 
„ bridge 
ignred text-fig. 94. The dimensions (in 
. ’ 10-7 
1A4 
14-4 
7-4 
3-7 app. 
7’5 
5-7 app. 
5-9 
R. 3346. Anterior portion of a mandible, })robabIy of this species. This mandible differs from that 
of P. madagascariensis in having a broader symphysis ; the biting surface is also much 
broader, and is partially divided into two by a median ridge. 
Genus STEREOGENYS, Andrews. 
[Geol. Mag. [4] vol. viii. (1901) p. 442.] 
This genus is nearly allied to Podocnemis, but is distinguished from it by: (1) the 
great length and massiveness of the mandibular symphysis ; (2) the posterior position 
of the internal nares resulting from the approximation of the palatines in the middle 
line to form a floor to the narial passage ; (3) the large size of the intergular shield, 
which separates the gular and humerals ; (4) the slight development of the axillary and 
inguinal buttresses. The fact that the anterior vertebral shield is narrower than the 
nuchal bone (in S. lihyca) was originally regarded as a generic character, but, as 
lleinach * has pointed out, it is doubtful whether this character occurs in all the 
species; the same is the case with the separation of the neural bones from the nuchal 
in front and the suprapygal behind. Reinach has lately described a species of this 
genus, S. podocnemioides, from the Middle Eocene of the Fayum, which in several 
respects, e. g. the relations of the intergular shield to the humerals, is intermediate in 
structure between the typical members of the genera Podocnemis and Stereogenys. 
Stereogenys cromeri, Andrews. 
[Plate XXV. flgs. 1-3 ; text-flgs. 95, 96.] 
1901. Stereogenys cromerij C. W. Andrews, Geol. Mag. [4] vol. viii. p. 442, fig. 4. 
1903. „ „ C. W. Andrews, Ann. & Mag. Nat. Hist. [7] vol. xi. p. 119, pi. viii. fig. 1. 
1903. „ ,, A. von lleinach, Abhandl. Senckenberg. naturf. Gesell. vol. xxix. pt. 1, 
p. 41. 
Type Specimen. — A skull and mandible (PI. XXV. figs. 2, 3); Geological Museum, 
Cairo. 
* Von Reinach, “ Schildkrdtem’este aus dem agyptischen Tertiar,” Abhandl. yenckenberg. naturf. 
Gesell. vol. xxix. pt. 1 (19U3) p. 34. 
