PISCES. 83 



sont tellement semblables au P. gigas du Portlandien qu'il est 

 presque impossible de les distinguer." 

 Localities. Upware, Brickhill, Potton. 



S. Europe. St Croix, Landeron, Neuchatel, Thoiry, Alle- 

 moque (dept. de 1'Ain). Urgonien and Neo- 

 comian (de Loriol and Gillieron). 



OTODUS, sp. 



A short and stout hastate tooth. The root is massive but not 

 expanded ; two slight enamelled eminences on its sides represent 

 the lateral denticles of the genus. 



Length. 1 inch. 



Some deeply biconcave sharks' vertebrae, measuring 1 3 inches 

 in diameter, are likely to belong to the same species. 



Localities. Upware, Brickhill, Potton. 



Besides these well-marked types, several other species of fishes 

 occur at Upware and Brickhill, and have been enumerated amongst 

 the ' derived ' fossils, though some of them may be proper to the 

 bed. There is a particularly fine dorsal spine of Asteracanthus 

 ornatissimus from Upware in the Woodwardian Museum, measuring 

 7 inches in length ; and the jaws of Ischyodus Townshendi are 

 found in fine condition both at Upware and Potton. Other species 

 of Chimeroid jaws also occur. 



