86 ANIMAL LIFE PAST AND PRESENT. 



easy to understand ; but it is possible that instead of 

 living on hard mail-clad fishes like their toothed cousins 

 of the Lias, their food may have been of a softer nature, 

 such as cuttle-fishes. 



In stating that the Fish-Lizards of the Lias subsisted 

 largely on the mail-clad " Ganoid " fishes of the same 

 epoch we may perhaps be thought to be drawing upon 

 our imagination. This, however, is not the case, since 

 we frequently find the whole contents of the stomach 

 of these reptiles preserved within the cavity of their 

 ribs, thereby showing that their food was composed not 

 only of these fishes, but also of young individuals of 

 their own genus. In very rare cases, moreover, there 

 are found within the body-cavity of large individuals 

 very small skeletons of other Fish-Lizards (Fig. 22) ; and 

 since these young skeletons are always entire and be- 

 long to the same species as the one within whose body 

 they are enclosed, it has been concluded that some 

 Fish-Lizards brought forth their young in a living con- 

 dition. This conclusion is certainly one of the most 

 startling and unexpected results which has rewarded 

 the students of this branch of palaeontology. 



Whether, when the name of Fish-Lizards was first 

 given to these saurians, it was in the mind of its author 

 that they were really related to fishes, cannot now be 

 certainly known. It has, however, been subsequently 

 suggested that these reptiles are the direct descendants 

 of fishes ; but since, like Whales, they breathed air by 

 means of lungs, a recent writer has pointed out that if 

 such descent were really the case it is almost certain 



