No. 18.] 



TRIASSIC FISHES OF CONNECTICUT. 



15 



Although forming the dominant feature of Silurian verte- 

 brate life, Ostracophores are nevertheless accompanied in the 



It 



Z.SJl 



Fig 2. Outlines of Acanthodian Fishes, illustrating their 

 gradual elongation in shape and loss of intermediate spines during 

 successive periods. A, Climatius scutiger Egerton. Lower Old Red 

 Sandstone; Scotland. B, Mesacanthus mitchellt (Egerton). Ibid. 

 C, Acanthodes sulcatus Agassiz. Lower Carboniferous; Edin- 

 burgh. D, Acanthodes gracilis. Roemer. Lower Permian; 

 Bohemia. a, anal fin; d, dorsal fin; i. sp., intermediate spines; 

 p, pectoral fins. (From Smith Woodward, partly after Traquair 

 and Fritsch.) 



