29G 
TERTIARY YERTEBRATA OF THE FAYt'M. 
In this species, 'svliicli is tlie type of the geinis, the shell is more depressed, wider 
and more uniformly oval than in S. llhyca from the Beds above. It also differs in 
])ossessing a com])aratively narrow nuchal bone, probably narrower than the anterior 
vertebral sliield; in the later form the reverse is tlie case. From S. iiodocnemioiden, 
Itcinach, of the same horizon, this species is distinguished by the fact that the humeral 
shields are widely separated posteriorly by the intergular instead of terminating at the 
same point. 
Form, cf JjOC. — Qasr-el-Saglia beds (Middle Eocene) : north of Eirket-el-Qurun. 
Text-fig. 05. 
Palatal view of skull of Stcreoijenys cromeri, restored. 
hoc., basiocciiiital ; ee.jit., ectopterygoid wing ; f.i.e., fossa into which the internal carotid opens ; f.m., foramen 
magnum; i.n., internal nares ; rn.r., maxilla; p./., jialatine foramen; parietal; ji]., palatine; 
premaxilla ; pterygoid ; <7., quadrate ; sue., siipraoecipital ; squamosal. About | nat. size. 
The skull (PI. XXV. figs. 1-3; tcxt-lig. 95) in its general structure is closely similar 
to that oi Podocnemis, but is broader and more depressed. The supraocci])ital {soc.) is 
produced backwards into a large median process, the upper surface of which a])pears ou 
the roof of the skull between the hinder ends of the jiarietals {pa.). These bones are 
very large, forming the greater ])art of the skull-roof; laterally they join the (piadrato- 
jugals andjugals in a straight suture, forming wuth those bones a complete covering 
for the temporal fossag as in Podocnemis. The frontals (/.) arc comparatively small, 
and extend forwards to about the middle ])oint of the orbits, -where they join the 
