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perty of the vermicular tribe. When he fwims forward, 
the undulation or wavy motion of the fin and carina be- 
gin from the upper part, and move downwards; but 
when he fwims backwards, and the tail goes foremoft, 
the undulations of the fin begin at the extremity of the 
tail or fin, and proceed in fuccellion from that back- 
wards to the upper part of the body ; in either cafe h*e 
fwims equally fwift. Every now and then the fifli 
lays himfelf on one fide, as it were, to reft himfelf, and 
then the four feveral divifions of his body abovemen- 
tioned are very diftincftly feen; videlicet^ the vermiform 
appearance of the two upper divifions ; the retiform ap- 
pearance of the carina ; and the laft, or dark-coloured 
fin, whofe rays feem to be exceedingly foft and flexible, 
and entirely at the command of the ftrong mufcular ca-- 
rina. When he is taken out of the water, and laid on his 
belly, the carina and fin lye to one fide, in the fame man- 
ner as the ventral fin of the I'etraodon does, when he 
creeps on the ground. I have been the longer and 
more particular in the defcription of the external ftruc- 
ture of this animal’s body, becaufe I think, as it is of a 
moft fingular nature, and endow^ed with fome amazing 
properties, even the moft minute circumftance I was able 
to obferve relating to it fhould be mentioned. 
The perfon to whom thefe .animals belong, calls 
them Eledirical Fijh\ and indeed the power they have of 
giving an ele6trical fliockto any perfon, or to any number 
of perfons who join hands together, the extreme perfon 
on each fide touching the fifla, is their moft fingular and 
VoL. LXV. Q aftonifliing 
