PODOCNEMIS PAJUMENSIS. 



293 



In the type of P. hlanckenhorni * 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 

 that 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. hlanckenhorni var. ovata f the entoplastral is similar to that of P. fajumensis, vphile 

 the grooves and sutures are nearly like those of the typical P. hlanckenhorni. Other 

 specimens of plastra still further bridge the gap between the two species : thus one 



Text-fig. 94. 



Carapace and plastron of (?) Podoenemis fajumensis : A, carapace ; B, plastron. 



abd., abdominal shield ; an., anal shield ; EnL, entoplastral bone ; Ep.p., epiplastral bone ; fern., femoral 

 shield : g., gular shield ; Ti., humeral shield ; Hy.f., hyoplastral hone ; Hyp.p., hypoplastral bone ; 

 i.g., intergular shield ; Ms.p., mesoplastral bone ; j^. 2-6, second to sixth neural bones ; peet., 

 pectoral shield ; Py. 1-2, pygal bones ; v. 2-4, second to fourth vertebral shields ; Xi.p., xiphiplastral 

 bone. 2 '^^*'' si^®' 



specimen has an entoplastral very similar to that of P. hlanckenhorni, 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 Eeinach'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. Ton Eeinach, op. cit. p. 27, pi. ix. figs. 3, 4. 



t A. Ton Eeinach, op. cit. pi. ix. figs. 1, 2. 



