1136 
SCANDINAVIAN FISHES. 
A : Teeth large or middle-sized. The gill- 
openings extend only slightly, if at all, 
above the middle of the sides. — Sub- 
family Lamnince. 
a: Length of the caudal fin about half 
that of the body or even greater. 
Peduncle of the tail not keeled Alopias vulpes. 
b: Length of the caudal fin much less 
than half that of the body. Sides 
of the peduncle of the tail furnished 
with a longitudinal carina in front 
of the caudal fin Isurus cornubicus. 
B: Teeth extremely small, numerous, of 
a simple conical form. The gill-open- 
ings extend up the greater portion of 
the sides. — Subfamily Selachince Cetorhinus maximus. 
Genus ALOPIAS. 
Caudal fin usually occupying more than half the length of the body. A transverse depression at its base above 
and beloiv. No lateral carina on the tail. Teeth middle-sized, of a compressed triangular form, smooth-margined. 
Of this genus, which possesses, in its so singularly 
elongated caudal fin, an unmistakable characteristic 
among all the Sharks, only one species is known. 
This is strictly a stranger to the - Scandinavian fauna, 
but has been met with three or four times within the 
limits thereof. 
THE FOX-SHARK (sw. rafhajen). 
ALOPIAS VULPES. 
Fig. 328. 
Body, apart from the caudal fin , of a thick fusiform shape, almost clavate , the least depth being only slightly less 
or even more than half the greatest, which is contained about 4 times in the length of the body , excluding the 
caudal fin. Length of the short conical snout about 1 / G — 1 / 5 of the interorbital width. Diameter of the eyes about 
half the length of the snout. Spiracles extremely small, situated in a groove exactly behind the eyes, from which 
they are separated by a distance equal to or half as great again as the diameter thereof. Gill-openings middle- 
sized (small, in comparison with those of the two following species ). First dorsal fin situated about half-way 
between the tip of the snout and the base of the caudal fin, triangular , with the lower inferior corner but slightly 
prolongated. Second dorsal and anal very small, the former situated about two-thirds of the way between the first 
dorsal and the caudal and with its base in front of the perpendicular from the beginning of the anal fin. Pec- 
toral and ventral fins rather large, especially the former , which are of a broad scythe- shape, their length being 
about V 4 of that of the body to the beginning of the caudal fin; ventral fins rather similar to the first dorsal. 
Caudal fin scythe-shaped, with a triangular flap near the tip of the inferior lobe. Coloration above slaty-gray, 
underneath white, these tivo colours being interspersed on the lower part of the sides. 
Fig. 328. Fox-Shark ( Alopias vulpes ), l / 8 nat. size. After Todd, in Brown-Goode. 
Syn. NXwnn]^, Aristot., De Anim. Hist., lib. VI, c-app. X et XI. 
Singe de mer, Bel., Nat., Divers. Poiss., p. 88. Vulpes, 
Rondel., De Pise., p. 387. Squalus cauda longiore quam 
ipsnm corpus, Art., Ichthyol., Gen., p. 68; Syn., pag. 96. 
