40o 



TE LEO ST EI 



Family Chirothricidae. Premaxillae very slender. Teeth small 

 or absent ; sometimes dermal scntes. The fins are remarkably large, 

 the pelvics being of enormous size, with some eighteen dermal rays, and 

 placed far forwards quite near the pectorals. The family is known from 

 the Cretaceous only. 



Fig. 391. 



Alepidosaurus ferox, I. owe. (From Jordan ami Evermann.) 



Chirothrix, P. and H. ; Telepholis, van der M. ; and Exocaetoides, 

 Davis — Cretaceous, Europe and Asia Minor. 



Family Cyprinodontidae. The mouth is protractile ; teeth are 

 present on the jaws and pharyngeals, but rarely on the palate ; the 

 palato -quadrate arch is more or less reduced. Not more than seven 

 pelvic dermal rays. The air-bladder may be lost. 



Fig. 392. 

 Cetomimus Gillii, G. and U. (From Jordan and Evermann.) 



The Cyprinodonts, which are often of extremely small size, 

 frequently exhibit remarkable sexual differences, the male being 

 smaller and more brilliant in colouring. In the male the anal fin 

 may be modified to serve as an intromittent organ (Fig. 393). They 

 are often viviparous. 



Procatopas is distinguished by having the pelvic fins far forward 

 below the pectorals, and Anableps by a remarkable adaptation of its 

 eyes for seeing both in the air and in the water as it swims at the 

 surface, the cornea being divided into two dissimilar halves (Fig. 394). 



