364 FOSSIL REPTILES. 



and facilitated its vision daring the night, It had, probably, 

 no external ear, and the skin passed over the tympanic bone, 

 as in the cameleon, the salamander, or the pipa, without even 

 becoming any thinner. 



It respired the air directly, and not through the watery 

 medium, like fishes, and was therefore often obliged to rise to 

 the surface to inhale it. Still, its short, flat, and undivided 

 limbs could permit it only to swim, and there is no appearance 

 that it could have crawled on the shore, even as well as the 

 seals. Had it the misfortune to be wrecked there, it must 

 have remained immovable, like the whales and the dolphins. 

 It existed in a sea where the mollusca, which have left am- 

 monites behind them, inhabited, and which, according to 

 all appearances, were species of sepia or pulps, which con- 

 tained in their interior (like the nautilus spirula of the 

 present day) those spiral and singularly chambered shells. 

 Terebratulse, and various species of oysters, alsa abounded 

 in this sea, and many kinds of crocodiles frequented its^ 

 shores, if even they did not inhabit it conjointly with the 

 ichthyosauri. 



We may assign with precision, at least in the species with 

 slender muzzle (/. tenuirostris)^ the proportions of the parts. 

 In a total length of three feet and a-half, the head and tail 

 each take up a foot^ and there remain a foot and a-half for the 

 trunk, at the two extremities of which are the fins, for one can 

 scarcely say that there has been a neck. The anterior fin, or 

 paddle, was seven inches and a half long, with a breadth of 

 nearly three inches. The hinder paddle was a little less both 

 in breadth and length. 



The head of /. communis^ possessed by the Baron, must 

 have been at least two feet and a-half in length : therefore, it 

 announces an individual nine feet long, or thereabouts. A 

 skeleton, discovered on the coast of Dorsetshire by Miss Mary 

 Anning, has, however, been referred to this species, though only 

 five feet long. In fact, the size may vary very considerably in 



