FOSSILS OF LIASSIC SYSTEM. 



57 



The I'CHTIIYOSAU'RUS (from the Greek ichthus, a fish, and sauros, a lizard 

 -Jiah-lizai d Jig. 81), must have resembled some huge fish, having an 

 exceedingly large head and very powerful tail. The spine consisted of] 



Fig. 81. I'chthyosau'rus communis. 



vertebrae or joints, besides those of the neck, which were united into a mass 

 of solid bone. The eye was an extremely powerful organ, "capable of 

 adapting itself," says Dr. Buckland, " to great changes of distance, and 

 great alterations in the amount of light in which it could be used ; giving 

 to its possessor the power of discerning a far-distant object, as well as ono 

 near at hand, and of pursuing its prey in the darkness of night, or the dim 

 obscurity of the depths of the ocean, as well as in the day-time or on land." 

 This animal had a wrinkled skin, like the whale, without scales. 



Fig. bx. F lei' siosau' r ti s dolichodeirvs 



The PKEI'SIOSAU'RUS (from the Gre^k ^fon, near, and sauros, a lizard or 

 reptile resembling a reptile Jig. 82) may be described as exhibiting the 

 head of a lizard, attached to a neck whose length was three, or, in some^ 

 species, even more than four times that of the head. The body appended 

 to this head and neck was comparatively small and fish-like ; the extremities 

 were large paddles, and the tail like that of the crocodile. The neck con- 

 sisted of upwards of thirty vertebrae or joints, and was very long and flex- 

 ible. Ansted. 



Fig. 83. Ptfroda'ctylus longiro'stris. 



40. We also find, for the first time, in the lia'ssic group, the 

 pterodac'tylus (from the Greek ptcron, wing, and daklulos, finger- 



