HAPLOMI 



617 



line. The teeth vary much in shape : cardiform, villiform, or 

 compressed, and bi- or tri-cuspid ; the palate is either toothless, or 

 teeth are present on the vomer. About 200 species are known, 

 mostly from the American continent, only about 3 being known 

 from other parts of the world, viz. Southern Europe, Southern Asia 

 and Japan, and Africa. In many species the sexes are dissimilar, 

 the female being larger and less brilliantly coloured, with smaller 

 fins ; the anal fin of the male may be modified into an intro- 

 mittent organ by means of which internal fertilisation takes place, 

 the ova developing in a sort of uterus, which the young leave in 

 a more or less advanced stage of growth. The most curious of 



Fig. 374. — Anableps tetrophthalmus, male, J uat. size. 



the Cyprinodontids is the genus Anableps, of Central and South 

 America, surface-swimming Fishes, the strongly projecting eyes of 

 which are divided by a horizontal band of the conjunctiva into an 

 upper part adapted for vision in the air, and a lower for vision in 

 the water, and the pupil is divided into two parts by a constriction ; 

 the larger species grows to the length of a foot. 



Fici. 375. — Distribution of tlie Cyprinodontidae. 



