Ch. XXL] 



LIAS — SAUKIANS. 



323 



beyond its osseous framework, and deviating widely in its fish-like rays 

 from the ordinary reptilian type. In fig. 41 7, the posterior bones, or 

 digital ossicles of the paddle, are seen near b ; and beyond these is the 

 dark carbonized integument of the terminal half of the fin, the outline 

 of which is beautifully defined.* Prof. Owen believes that, besides the 

 fore-paddles, these short and stiff-necked saurians were furnished with a 

 tail-fin without radiating bones, and purely tegumentary, expanding in a 

 vertical direction ; an organ of motion which enabled them to turn 

 their heads rapidly .f 



* Geol. Soc. Transact. Second Series, vol. vi. p. 199, pi. xx. 

 f GcoL Soc. Transact. Second Series, vol. v. p. 511. 



