280 



TEETIAET VEETEBEATA OF THE FATtTM. 



and posteriorly the marginals (M. 1-11) are somewhat everted, but in the region 

 of the junction with the plastron they are vertical. The angles of the bridge between 

 the plastron and the carapace are greatly thickened and form a prominent border, 

 upon which the shell rests. 



The plastron (PI. XXIV. fig. 1 b ; text-fig. 89) is larger and the openings of the shell 



Text-fig. 89. 



Plastron of Testudo ammon. 

 aid., abdominal shield; an., anal shield; Mit., entoplastral bone; Ep.p., epiplastral bone ; /«m., femoral 

 shield; g., gular shield; h., humeral shield; ffyjo., hyoplastral bone; Hyp.p., hypoplastral bone; 

 peet., pectoral shield ; Xip., xiphiplastral bone. About ^ nat. size. 



are smaller than in most of the recent giant Land-Tortoises. In some individuals, 

 including the type, the epiplastral region {Ep.p.) is prolonged forwards to a greater or 

 less extent : as these have a deeply concave plastron, they are probably males. In the 

 specimen figured on PI. XXIV. fig. 1 b, however, this projection is very slight : as the 

 concavity of the plastron in this shell is very slight, it may be regarded as belonging to 



