LAMNA. 



207 



T^ipc. — Detached teeth probably from Turonian zones near Lewes ; British 

 Museum. 



Specific Characters. — Teeth robust, sometimes attaining a total height of 4 cm., 

 but usually smaller. Outer coronal face slightly convex or flat, often with few 

 indefinite vertical folds in the basal half ; inner coronal face very convex, smooth ; 

 cutting edges prominent ; a single pair of lateral denticles, broad but pointed. 



Fig. 63. Lamna appendiculata, Agassiz ; associated set of teeth, nat. size. —Zone of Holaster subglobosus ; 



Dover. Gardner Collection (B. M. no. P. 45). 



Root very thick, having a much-flattened postero-iuferior face, with no groove for 

 the nutritive foramen. Anterior teeth narrow and upright ; hinder lateral teeth 

 much inclined backwards, the anterior edge being more arcuate and longer than 

 the posterior edge. 



Description of Specimens. — Most of the detached teeth selected by Agassiz as 

 the type specimens of this species were obtained by Mantell from the Chalk near 



FiG. 64. Lamna appendiculata, Agassiz; associated set of teeth, nat. size. — Zone of Holaster subglobosus ; 

 near Maidstone. Bowerbank Collection (B. M. no. 39053). 



Lewes. The variations in shape in different parts of the jaw correspond with those 

 observable in the dentition of the existing Lamna (Text-fig. 62), as shown by the 

 associated sets of teeth represented in Text-figs. 63, 64 In both these specimens 

 there is a diminutive robust tooth, with a narrow elevated croAvn and closely 

 adpressed lateral denticles, evidently the same as the dwarfed tooth which always 

 occurs in Lamna in the third place from the front of the upper jaw. In the 



