ro DOCNEiAI 1 S FA J UMENSTS. 
293 
In the type of P. hlancJccnliorni* the entoplastral is more elongated and its postero- 
lateral borders are convex ; the groove between the humeral and pectoral shields 
curves backwards and crosses the suture between the epiplastra and hyoplastra, so 
tliat this form differs from the type of the present species both in the shape of the 
entoplastral and in the relations of the grooves and sutures. In the type of 
P. hlancJcenhorni var. ovata"\ the entoplastral is similar to that of P. fajuinensis, while 
the grooves and sutures are nearly like those of the typical P. hlancJcenhorni. Other 
specimens of plastra still further bridge the gap between the two species : thus one 
Text-fig. 94. 
Carapace and plastron of (?) Fodooiemis fajumensis : A, carapace ; B, plastron. 
abcl., abdominal shield; an., anal shield; Ent., entoplastral bone; Ep.p., epiplastral bone;/r!)i., femoral 
shield; g., gular shield; h., humeral shield; ITij.p., hyoplastral bone; Ihjp.p., hypoplastral bone; 
\.g., iutergular sliield ; Ms.p., mesoplastral bone; A. 2-G, second to sixth neural bones; pect., 
pectoral shield ; Pg. 1-2, pygal bones ; v. 2-4, second to fourth vertebral shields ; Xi.p., xiphiplastral 
bone. I uat. size. 
specimen has an entoplastral very similar to that of P. hlancJcenhorni, while the humero- 
pectoral grooves, although they curve backwards, do not cross the sutures between the 
epiplastrals and hyoplastrals. From the above observations it appears that it may be 
fairly assumed that all the specimens referred to are individual variations of a single 
species, and that Ileinach’s specific name is synonymous with P. fajumensis. 
The best specimen of this species is a nearly complete shell preserved in the 
Geological Museum at Cairo (C. 8790) and figured in text-fig. 94. The carapace is 
* A. von Eeinach, op. cit. p. 27, pi. ix. figs. 3, 4. ■ t A. von Keinach, oj). cit. pi. ix. figs. 1, 2. 
