174 PICTURESQUE SKETCHES 



consisted of a flattened tube, twisted into a spiral or 

 corkscrew form, and reduced to the smallest possible 

 dimensions. 



Judging from the existing reptiles, and the gigan- 

 tic sauroid fishes of the older period, it might per- 

 haps have been anticipated that the marine saurians, 

 of which the Ichthyosaurus is one of the most import- 

 ant genera, should be provided with hard bony plates, 

 or scutes, as they are called, at once enclosing and 

 defending the animal. The absence of such scutes 

 among the fossils of the lias, which has not only 

 retained and handed down all the hard parts in great 

 abundance and perfection, but exhibits even some of 

 the softer portions of the body, would alone render 

 this questionable. But the doubt has been completely 

 justified by the discovery of actual portions of the un- 

 defended skin, which, preserving the analogy with the 

 cetaceans, appears to have been naked, of considerable 

 thickness, and covered with minute folds and wrinkles 

 on the belly, instead of scales. 



Fig. 64 



ICHTHYOSAURUS. 

 (Restored Outline.) 



On the whole, then, the Ichthyosaurus may be de- 

 scribed as an air-breathing reptile, which sometimes 

 attained a length of thirty to forty feet, which was co- 

 vered like a whale with smooth, naked, thick skin, and 



