1086 
SCANDINAVIAN FISHES. 
PLAGIOSTQMI BATOIDEP. 
Base of the pectoral fins extended backwards along the sides of the body and forwards along those of the head , 
above the five branchial apertures. Tail slender, terete ( whip-like ) or depressed. No anal fin. 
All the vertical fins belong to the tail. 
The most important distinctions between the Rays 
and Sharks we have already mentioned in the intro- 
duction to the Elasmobranchs. They are bound up with 
the different habits of these fishes. Nearly all the Rays 
are ground-swimmers and live in the same manner as 
the Flounder-fishes, only seldom attempting rapid ex- 
cursions or movements in the water. The above-men- 
tioned intermediate forms — the well-known Saw-fishes 
( Pristis ) and their nearest relatives, without a saw, the 
Rhinobatidce, a family common principally in Indian 
waters — therefore approach, in their way of life as 
well, the transition to the Sharks. 
Among the vital capacities of the Rays one, namely 
the power of giving electric shocks, possesses a special 
interest. Not only is this faculty a rare phenomenon 
in the whole animal kingdom and the peculiar property 
of fishes — even among these it is shared, in a singular 
and hitherto unexplained manner, by representatives of 
widely separated orders and families. At least two 
Teleosteous families * 6 are endowed with this power, and 
a third c possesses it in so slight a degree that doubt 
is still felt whether this family should be included 
among the electric fishes or not; but none of these 
Teleosts is so nearly connected with the Scandinavian 
fauna as to have induced us to describe its faculties. 
That electricity is really present both in muscles 
and nerves, or, to express ourselves more cautiously, 
that at least under certain circumstances electricity 
may be stored in muscles and nerves, has long been 
known; but nowhere has this electricity such an oppor- 
tunity of accumulating as in certain fishes. The earliest 
and best known among these fishes are the Electric 
Bays. Their family, the Torpedinidce, is fairly rich 
in forms: about 20 species, distributed among 6 genera, 
have been described with varying accuracy from the 
tropical and temperate seas. Three of them — ■ Torpedo 
nobiliana, Torp. ocellata ( narce ), and Torp. marmorata — 
live in the Mediterranean and the adjoining parts of 
the Atlantic, the last-mentioned species being besides 
an inhabitant of the Indian Ocean. 
The power possessed by the Electric Rays of ac- 
cumulating electricity in their organs and voluntarily 
discharging these at need has been known at least since 
the time of Aristotle and Theophrastus; and Roman 
physicians, when Galen lived, if not before, employed 
these Rays in the treatment of gout and nervous dis- 
eases. In recent times this electricity has been more 
minutely studied, and has been found to be identical 
in its effects with other electricity. It has the same 
influence on the magnetic needle, it can decompose 
chemical compounds, and it emits the electric spark. 
When the Neapolitan fishermen have drawn their seines 
ashore, it is usually, according to Owen, their first 
care to pour a bucket of water over the catch. If the 
net contains an Electric Ray, its presence is at once 
betrayed by the shock transmitted along the stream of 
water to the hand holding the bucket. To handle a 
live Electric Ray is unpleasant enough, for the arm at 
least is paralysed by the shock for a long while. 
Like the still more powerful Electric Eel — which 
is not an Eel, though it has the external appearance 
of one, but rather a Sheatfish, an inhabitant of fresh 
water in tropical South America — these Rays employ 
their electric power both to kill or at least to stun 
their prey and to defend themselves against their ene- 
mies. The other electric fishes known to us are far 
inferior in their capacity of accumulating electricity, 
and probably have recourse to this faculty in defence 
alone. Other fishes again scarcely have the power of 
giving appreciable electric shocks, but possess true elec- 
tric organs, which on account of their feebleness have 
been called pseudoelectric. Such organs appear in se- 
veral of our common Rays. Their strength is not 
great, and it has seldom been observed; but in 1888 
? Gr. ficcTog, Ray. 
6 Fain. Gym.notidce (Electric Eels) and the subfamily Malapterurince of the great Sheatfish family. 
c Fam. Mormyridas. 
