RAIA. 



313 



II.- 



Phylum - 



Sub-Phylum 



Class 



-RAIA. 



Chordata (p. 403). 

 Vertebrata (p. 406). 

 Pisces (p. 435). 



Raia radiata"" is one of the commonest of the British 

 skates, and is perhaps the most convenient as regards size. 

 The other species only differ in size, colour, general shape 

 of the body and other small structural features. 



The skate lives near the bottom at moderate depths, 



and is carnivorous in diet. In shape its body is rhomboidal, 



with a long tail depending from one angle. The 



body is flattened dorso-ventrally, the two large 



side-flaps being made up of the enormously 



expanded pectoral and fairly large pelvic fins. Attached 



Fig. 226.— Jaws and Teeth of (A) Male and 

 (B) Female Skate. 



to the pelvic fins in the male is a pair of large claspers. 

 These fins represent the front and hind-limbs respectively 

 of the higher Vertebrata. 



The pointed anterior end is termed the rostrum. 



"^ The following description will apply for the common British species, Rdia 

 inaculata and Raia baits. 



