356 
SCANDINAVIAN FISHES. 
era; but the distinction of the species is still extremely 
dubious, this being due chiefly to our ignorance of the 
changes of growth, especially in the coloration. The 
most important characteristic employed in the definition 
of the genera, lies in the position of the ventral fins. 
Each of the two species of which Ave have the earliest 
knoAvledge, has therefore been chosen as the repre- 
sentative of a distinct genus, the one" with the ventral 
fins situated rather far fonvard and comparatively small, 
the other, Exocoetus , with the ventral fins larger and 
set farther back. Swainson also formed a distinct 
genus 6 to receive the species that are furnished Avith 
barbels under the point of the chin; and Bleeker es- 
tablished a genus 0 consisting of the species Avhich, on 
account of the knob-shaped, rudimentary elongation of 
the loAver jaAv, seem to form a transition from this 
subfamily to the preceding one. 
None of these genera can strictly be included in 
the Scandinavian fauna; but in Christiania Fjord a spe- 
cimen has once been taken of the 
Genus EXOCOETUS. 
Ventral fins behind the middle point in the distance between the tip of the snout and the base of the caudal fin, 
and their tip ( when folded ) extending beyond the beginning of the anal fin. Palate and tongue toothless , or the 
palatine bones alone slightly rough with small teeth. 
Thus defined the genus Exocoetus includes the most 
typical Flying-fishes and the largest number of described 
species Avithin the subfamily. The name of exocoetus d 
originally had reference to a fish that the ancients sup- 
posed to creep up on a rock to sleep. We do not 
know what fish this Avas — perhaps a Gobioid, as Ron- 
delet 0 supposed; but it Avas certainly not a Flying- fish, 
as ArtedC assumed, and Linn a: us subsequently took 
for granted. HoAvever, the singular appearance of the 
Flying-fishes and their valuable flesh must certainly 
have given them prominence at an early period, and 
according to Salvianus their Greek name Avas chelidon \ 
just as the Romans called the genus hirundo. The 
geographical extension of the genus is the same as that 
of the Sauries, and several species — as clearly defined 
as our present knoAvledge of them permits — deserve 
the name of cosmopolitan in the seas of the Tropical 
and Temperate Zones. 
a Halocypselus, Weinland, Proc. Soc. Nat. Hist. Bost. VI (1859), p. 385. 
b Cypsilurus , Nat. Hist. Fish., Amph., Rept., vol. I, p. 299, vol. II, pp. 187 and 296. Weinland (1. c.) corrected this generic 
name to Cypselurus ; and Gunther remarked (Cat. Brit. Mus., Fish., vol. VI, p. 278) that, in certain species at least, the generic character 
is merely an evanescent character of the young specimens. 
c Par exocoetus, Esp. Exoc., Ned. T. Dierk., Ill, p. 126, see Atl. Ichth. Ind. Or. Neerl.. tome VI, p. 77. Bleeker has also given 
the presence of teeth on the vomer, the palatine bones, the pterygoid bones and the tongue as a character of this genus. 
d E±iu'/.oiTog, sleeping out. 
e De Pise., lib. VI, cap. XV. 
f Gen. Pise., p. 8; Syn. Pise., p. 18. 
9 Xelidiov, swallow. 
