50 PAL^ONTOLOGICAL RESEARCHES. 



from botli in the small size and acuminated shape of 

 the anal and ventral fins, and in the extraordinary de- 

 velopment of the caudal, the vertebrated portion of 

 which rose almost perpendicularly to * one-third the 

 length of the animal. From the sail-like appearance 

 of the dorsal and caudal fins, Goodsir proposed for the 

 genus the provisional name Istiopterus. Two of the 

 five species belonged to this genus. These fishes were 

 all highly heterocercal, and in none of them was there 

 any trace of the pectoral fins. 



At a subsequent meeting he presented another 

 fossil fish, also new, from the Cornceres quarry, 

 which, in general appearance, approached the genus 

 Amhlypterus, but differed from it in the fins being 

 triangular instead of quadrilateral, and resembling 

 more the provisional genus Istiojrterus, which he had 

 previously proposed. All the ichthyolites from the 

 Cornceres quarry were referable to the Ganoid order 

 of Agassiz. The coprolites and detached teeth he 

 considered indications of the former existence of a fish 

 belonging to the Sauroid family of the Ganoid order. 

 All the other fossils he showed were referable to the 

 Lepidoid family ; and these, nine in number, he 

 described particularly. His frequent visits to Corn- 

 ceres, and his apt observations of the fossilised forms 

 found there, led many of his friends to suppose that 

 he was now aiming at palaeontology, his initiative in 

 that direction of study offering high promise. 



At another meeting he submitted specimens of two 

 species Beroe, discovered by his friend Edward Forbes, 



