PUurodiran Chelonians from Egypt. 121 



narrows suddenly, so that its outline, as a whole, is somewhat 

 pear-shaped. 



There are six neurals, the anterior one beino- in contact 

 with the nuchal in front, while the hinder one is separated 

 from the suprapjgal by tlie union of the hinder portions of 

 the sixth pair of costals and of the seventh and eighth pairs 

 in the middle line. The anterior neurals are much lon<^er 

 than broad, and their antero-lateral borders are much shorter 

 than tlieir postero-lateral ones. The last neural terminates 

 posteriorly in a point and is pentagonal. There are eight 

 pairs of costal bones, the first, as usual, being much t\\Q, 

 largest. The nuclial is wide and its anterior border is nearly 

 straight and without any emargination. There is a lacuna in 

 the shell at the junction of the nuchal, the first neural, an I 

 the first costal. The marginals are not well preserved, there 

 are ten or eleven pairs of them. The suprapygal is rouglily 

 triangular in form. 



The Plastron.— In the plastron (see PI. VIIT. fig. 2, B) 

 the entoplastral bone is rhomboidal in form and the sutures 

 between the epi- and hyoplastrals run outwards and backwards 

 from its outer angles and then turn forward ; the sutures are 

 very complex, the different elementsinterdigitating very deeply. 

 The suture between the hyo- and hypoplastral crosses about 

 the middle of the bridge and terminates at each end in a 

 small mesoplastral. 



The bases of the pubis and ischium are fused to the plastron 

 in the manner usual in the group. Unfortunately all traces 

 of the grooves marking the boundaries of the epidermal 

 shields are wanting both in the carapace and plastron. 



The small size of this tortoise and the fact that it is found 

 in the same beds as Stereogenys Cromeri may give rise to the 

 suspicion that it is the young of that species ; but the differ- 

 ences above described are so considerable that it seems 

 advisable to regard it as a distinct species until the contrary 

 is proved. 



The dimensions of the type specimen of Podocnemisantiqua 

 are : — 



centim. 



Total length of the shell 20-2 



„ „ plastron 18-6 



"Width of anterior lobe of the plastron 10 



„ posterior „ „ 8-5 



Approximate width of carapace 20 



Podocne7m's fajumensi's, sp. n. (PI. VIII. fig. 2, C) 

 In the Upper Eocene beds remains of another small 

 Pleurodiran are not uncommon. This species differs widely 



