82 
SKATEf?. 
rals; and the combined use 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 vcntrals, 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 great 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 
vertebrae 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 effective 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 
arc 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 nature 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 are fitted to withstand. 
In the young of the generality of this order, as they 
