216 The Hijlory of ANIMALS. 
opening of the mouth is not large : the lower jaw, when the mouth is open, appears' 
fomewhat longer than the upper; the noftrils are large, and ftand nearer to the eves 
than to the extremity of the roftrum ; there is a kind of appendage in the middle 
which makes each feem as if formed of two apertures: the eyes are very large and 
round ; their iris is of a filvery colour, and the pupil is round : the apertures of the 
gills are not large ; there is in each jaw a fingle row of very minute teeth 5 thofe on the 
under jaw in particular are fo very fmall, that they are fcarce vifible: 'the fcales are 
large, hard, ftnooth, and whitifh 5 they are, in general, of a femicircular, fome of a 
fomewhat angulated, figure, and toward the bafe or anterior part they have three, four 
or more, large ftria? ; they ftand thick together, and, as it were, in firaight rows * 
the colour on the back is a dulky brown j the belly and tides are of a fine filvery 
white ; there is no lateral line in the accuftomed place on the fides, but in the lower 
part of the body, at the fides of the belly, there run two genuine lines formed of fcales, 
perforated in their center, and,in all refpeds but the place, anfwering to the characters of 
the lateral lines in other tithes. 
The peCtoral fins, in this fifh, are extreamly fingular; they are fituated juft below 
the extremity of the covering of the gills on the fides, but elevated toward the back ; 
they are not affixed horizontally, but in an inclined plane at the bafe, and are fo long' 
that they equal the whole body of the fith, reaching to the beginning of the tail • 
they are not very broad, and each of them has feventeen nodofe rays, ramofe at the 
ends: the membrane which connects thefe, and forms the fin, is fmooth on the upper 
fide, but underneath there are hollows between the feveral rays: the ventral fins are 
fituated on the lower part of the belly, not far from the anus j they are of an oblong 
figure, white, and ftand at a great diftance from one another; each of thefe has fix 
rays, all of them ramofe at the extremity : the pinna ani is white and fmall 5 it has 
eleven thort and foft rays: the dorfal fin is not large, and is fituated toward the hinder 
part of the body; it is whitifh in colour, and has eleven fhort and foft rays: the tail 
is very forked, and has fifteen long rays: the branchis are four on each fide, and are 
formed as thofe of the pearch, each having a double row of tuberculous and fomewhat 
rough apophyfes. 
It is caught in the Mediterranean, and fome other feas. The antient Greeks called 
it ’E^W- t(& and ’AJovk, Exocaetus and Adonis; and the Latins borrowed both thefe 
names from them : fome have called it Exochinos, and other Mugil alatus and Hirun- 
do pifcis j fome have thought the Hirundo pifcis and the Exocastus different, but with¬ 
out reafon ; the Italians call it Pefce Rondine ; and Salvian take great pains to prove 3 
that it was the Xi^^v r Chelidon, of the antient Greeks. 
The ufe it makes of it’s peCtoral fins is very fingular ; they ferve it for flying, but 
this only in a limited manner; the fifh has a power of throwing itfelf into the air 
from the furface of the water, and, when it is there, it fufpends itfelf, and moves for¬ 
ward very nimbly by the motion of thefe fins, which ferve it as wings 5 but when 
they become dry, as they foon do in the air, they are unfit for any farther fervice of 
this kind, and the creature drops into the water again. It finds a means to efcape the 
purfuit of fome larger fifh, by means of thefe wings j but this often expofes it to new 
danger, for, when in the air, it becomes the prey of the fea-birds. 
COREGONUS. 
T H E dorfal fin of the Coregonus is placed nearer the head than the ventral ones 
are : the teeth are very fmall $ in many fpecies they are fo remarkably fo, that 
they are hardly vifible: the branchioftege membrane on each fide has feven, eight, 
nine, or tep bones in it. 
Coregonus edentalus maxilla mferiore longiore. 
The Coregonus ? with no vifible teeth , and with the lower jaw longefl. 
The head is oblong, fomewhat acute and comprefled, and in the upper part is fome¬ 
what pellucid : the eyes are large, and their iris is of a filvery colour : the lateral line is 
ftraight, and is nearer the back than the belly ; the fcales are moderately large, and of a 
filvery colour ; they are oblong, fmooth, and but flightly affixed to the body : the back 
is all the way convex ; the belly is flat from the place of the peCtoral to that of the ven- 
