82 SKATES. 



rals; and the coinbinrd ii«e of both is to raise the body from 

 its usual prone position on the ground, and to sustain it in 

 a floating posture, but without much power of propulsion. To 

 the vontrals, on their inner side in the males the claspers are 

 attached, which are usually much longer and stouter than 

 in Sharks, and which, by a complex system of joints, admit 

 of jjreat variety of motion. 



As there is less need of flexibility in the body of this class 

 of fishes than in the kindred family of Sharks, several of the 

 vertebra; or jointed bones of the back, near the head, are 

 consolidated into one, by which the stability of that part is 

 rendered secure; but if any deficiency of motion could arise 

 from this cause it is abundantly compensated for by the 

 flexibility of the tail, which has no caudal plates or processes 

 to stand in the way, and which therefore is capable of action 

 in every direction. It is therefore not only eficctive in driving 

 onward or steering the body, but also as a weapon of defence; 

 for being generally armed with rows of formidable spines, it 

 is capable of inflicting severe lacerations on any creature that 

 comes within its reach. Aided by the pectoral fins, which, 

 especially in the males, are also well furnished with these crooked 

 spines, they are indeed weapons to be dreaded, and the species 

 supplied with them appear to be well acquainted with their 

 use. This instinctive faculty of knowledge is indeed a won- 

 derful portion of the history of animals, even of those that 

 are apparently most dull and stupid, and has been noticed 

 by observers of ancient as well as modern times. Oppian, in 

 his imperfect poem, the "Halieuticon," observes, — 



"To all is given 

 To know the power and uatui-e of the dart." 



In self-defence not only will the Torpedo discharge its electric 

 shock, and the Fireflair direct its formidable spear, but the 

 Common Skate will bend its pectoral fins into a concave form 

 to encircle the object, and then cause them to draw back 

 that the beds of spines may rasp the body of its enemy; 

 whilst the still more formidable tail is brandished over all in 

 a manner that few creatures arc fitted to withstand. 



In the young of the generality of this order, as they 



