208 CHELONIA. 



28618*. Slab showing the dorsal aspect of the entire carapace ; 



{Fig.) from the Purbeck of Dorsetshire. Figured by Owen, op. 

 cit. pL vii. as Pleurostemum ovatum, of which it is the type. 

 The 4th neural is absent, so that the 4th costals meet in 

 the median line ; the 8th neural is small and distinct from 

 the suprapygal. The nuchal is as wide as in No. 38733 

 but has no distinct emargination. 



Willcooo Collection. Purchased, 1853. 



47401. An imperfect and flattened carapace apparently belonging 

 to this species ; from Swanage. The nuchal is wanting. 

 The ventral surface shows that the ilium had but a small 

 osseous connection with the 8th costal. 



Purchased, 1876. 



38733. Slab exhibiting the dorsal aspect of the somewhat imperfect 

 carapace ; from Swanage. The nuchal is relatively wide 

 and slightly emarginate ; and the 8th neural is exceedingly 

 minute. Purchased, 1865. 



21351*. Slab showing the dorsal surface of an imperfect carapace 

 in which the nuchal is wanting ; from Swanage. 



Purchased, 1847. 



28619. Slab showing the dorsal surface of the posterior extremity 

 of the carapace ; from the Purbeck of Swanage. This 

 specimen shows the 7th and 8th neurals, suprapygals, 

 and the 7th and 8th costals, together with the detached 

 6th costal of the right. The 8th neural** has coalesced 

 with the 1st suprapygal. Willcox Collection. 



24298. Slab showing portions of the carapace ; from the Purbeck 

 of Swanage. The ventral aspect of the posterior extremity 

 is well displayed. The small surfaces for iliac attachment 

 are shown ; and the ilium and ischium of the right side 

 are also preserved, the distal extremity of the latter being 

 expanded. Cunnington Collection. Purchased, 1849. 



38733. Slab exhibiting the dorsal aspect of the imperfect carapace, 

 the ventral surface of the right side of the posterior half 

 of the plastron, and the pectoral girdle of the left side ; 

 from the Purbeck of Swanage. The coracoid is greatly 

 expanded distally, and closely resembles that of Chelys ; 

 but the scapulo-precoracoid (as shown by No. 4S351, infra) 



