Oa XXL] 



LIAS — SAURIANS. 



323 



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

 from the ordinary reptilian type. In fig. 417, the posterior bones, or 

 digital ossicles of the paddle, are seen near h ; 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. 



