CHONDROPTERYGII. 191 



Raid* the Skate. 



The true Rays present most obviously the cha- 

 racters we have already mentioned ; their disk is 

 rhomboidal, their tail long and slender, and fur- 

 nished near the tip with two small dorsals ; on the 

 tail are usually one or more rows of sharp points, 

 and in some species the whole disk is studded with 

 points rising from a broad base, and resembling 

 the spines of a rose, as in the common Thornback 

 (JR. Clavatd). A Skate's " mode of defending it- 

 self, as described by Mr. Couch, is very effectual: 

 the point of the nose and the base of the tail are bent 

 upwards towards each other ; the upper surface of 

 the body being then concave, the tail is lashed 

 about in all directions over it, and the rows of sharp 

 spines frequently inflict severe wounds." f The 

 young of the Rays are produced in horny cases 

 resembling those of the Sharks. 



Trygon,% the Sting -ray. 



This genus is distinguished from the common 

 Rays by the tail being armed near the base with 

 a very hard and sharp-pointed spine, with serrated 

 edges ; the rest of the tail is slender, and tapers 

 to a long point without any fin. A species called 

 the Fire Flaire (T. Pastinaca) is now and then 



* Its Latin name. f Yarrell, Br. Fish. ii. 415. 



J Its Greek name. Pastinum, a two-pronged fork ? 



