292 
TERTlAliY VERTEBRATA OF THE FATtM. 
In tills species the anterior lobe of the plastron is longer compared Avith the 
])osterior lobe than in P. antUiua, and the outline of the shell is more regnlarly oval 
than in that species. Its probable identity with P. hUmckenhorni, Keinach, is referred 
to below. In P. agijptiaca from the Lower Miocene of Mogara, the lobes of the 
l)lastron are longer in proportion to their Avidth and the form of the vertebral shields 
is different. 
Form. & Loc. — Fluvio-marine beds (Upper Eocene) : north of Cirket-el-Qurun. 
Ilemains of small Podocnemid tortoises are fairly numerous in the Upper Eocene 
beds, the anterior part of the plastron, for some reason or other, being most commonly 
found. One of these was made the type of the present species Podocnemis fajumensis, 
Avhile others have been described by Ileinach under the names P. hUmckenhorni and 
P. hlanckenhorni var. ovata, the chief differences betAveen the tAvo species lying in 
the form of the suture betAveen the epiplastrals and hyoplastrals and of the groove 
Text-fig. 93. 
Anterior portion of plastron of Podocnemis fajumensis (type spcfiinen). 
Ent., entoplastral bone; Ep., epiplastral bone; <j., gular shield; Ify.p., byoplastral bone; L/., intergular 
shield ; Ms.p., uiesoplastral bone; n., luuneral shield; p., pectoral shield. -3 nat. size. 
(From the Ann. & Mag. Nat. Hist. [7] vol. xi.) • 
between the liumeral and pectoral shields. Several other specimens have been 
examined, and it is found that a considerable degree of individual variation exists 
in this respect, so that it is not impossible that the different forms described may 
be merely variants of one species, although further more satisfactory material Avill he 
necessary to settle this point. 
In the type specimen (text-fig. 93 ) the anterior border is rounded, Avith slight notches 
marking the boundaries of the areas covered by the epidermal shields. The anterior 
lobe Avidens gently toAvards the bridge. The ento])lastral is diamond-shaped, all the 
sides being nearly straight. The suture hetAveen the epi- and hyoplastrals runs a little 
backAvards from the outer angle of the entoplastral, then IbiAvards and outAvards 
])arallel Avith the humero-pectoral groove, Avhich is about Vo cm. in front of it. 'Fhe 
intergular is small, the gulars longer, meeting in the middle line for about 1 cm. 
The humerals extend back to about the middle of the entoplastral bone (text-lig. 93 ). 
