PLATE XXVI. 



Fig. Page. 



1. ThHssops curtus, sp. nov. ; right lateral view of fish, nat. size. — Lower 



Purbeck Beds; Isle of Portland. The type specimen. British 

 Museum, no. P. 10612. 137. 



2. ThHssops molossus, sp. nov. ; left lateral view of fish, two-fifths nat. size. 



— Middle Purbeck Beds; Swanage. British Museum, no. P. 417". 138. 



3. Hybodus basanus, Egerton ; cranium, upper and (3 a) posterior views. 



one-half nat. size. — Weald Clay; Atherfield, Isle of Wight. Col- 

 lection of Reginald W. Hooley, Esq., F.G.S. f.m., foramen magnum ; 

 //., pit for notochord; p. f., posterior fossa or fontanelle ; r., pair of pits 

 into which the vagus nerves probably opened. 139. 



I. Lepidotus minor, Agassi z ; imperfect fish, left lateral view, showing 

 dorsal fin, one-third nat. size. — Middle Purbeck Beds; Swanage. 

 British Museum, no. P. 12211. 140. 



