STEREOGENTS LIBYCA. 



oUo 



the anterior and posterior costals respectively. The distance between the anterior 

 neural and the nuchal is 4-6 cm., that between the last neural and the suprapygal 

 1-9 cm. The anterior neurals are much longer than wide, but the series shortens 



Text-fig. 97. 



9 W 



Carapace and plastron of Stereogenys libyca : A, carapace ; B, plastron ; C, shell from right side. 

 £nt., entoplastral bone; g., gular shield; Si/.p., hyoplastral bone; Hyp.p., hypoplastral bone; ig., inter- 

 gular shield ; Ms.p., mesoplastral bone ; n., humeral shield ; Nu., nuchal bone ; peel., pectoral shield ; 

 Pyg.-, pygal bone ; v. 1-5, vertebral shields ; Xi.p , xiphiplastral bone. ^ nat. size. 



(From the Ann. & Mag. Nat. Hist. [7] rol. xi.) 



from before backwards, so that the posterior ones are wider than long. They are 

 hexagonal in outline, with the exception of the first and last, which are pentagonal, 



