ICHTHYOSAURS. 



Arabian Chamcdeou cahjptratus (45 1 ), of which a specimen is exhibited, 

 the body is marked by vertical bands of blue and yellow. All the 

 species are confined to the warmer parts of the Old World. 



The Common Chamseleon (Chamceleon vulgaris) ; § uat. size. (No. 44-6 ' 



Order VII.— IOHTHYOPTERYGIA (Extinct). 

 (Case 17.) 



The Ichthyosaurs were AVhale-like marine Reptiles which nourished 

 from the period of the New Red Sandstone, or Trias, to that of the 

 Chalk. The limbs are modified into paddles, in which the bones 

 of the digits exceed the normal number, and are more or less 

 shortened and broadened so as to form a pavement-like structure. 

 The teeth, which are generally fluted, are implanted in grooves in 

 the long jaws. A ring of overlapping bones is developed in the 

 white (sclerotic) of the eye. The bodies, or centra, of the vertebras 

 are short, doubly-cupped, and separate from the neural arches. 



The Triassic Merriamia and Mixosaurus were comparatively small 

 Reptiles, in which the ribs of the trunk are single-headed, the radius 



