SHARKS. 
1149 
THE BLACK-MOUTHED DOG-FISH (sw. hagalen). 
PRISTIURUS CATULUS. 
Plate LI, fig. 2. 
Coloration above of a reddish or brownish gray, with spots darker than the ground-colour but with a lighter 
border, and varying in size and form, usually larger, quadrangular or rounded, next the back, smaller down the sides. 
Dorsal fins behind, the other unpaired fins at the base more or less cinereous, at the tops darker. Pectoral and 
ventral fins of the same colour as the back or sides, but immaculate, paling outwards. Ventral side white. Mouth 
and pharynx, as well as the branchial cavity and peritoneum, black. Iris light blue. 
Syn. Haae-Gicele, Strom, Sondm. Beskriv., part. I, p. 283. 
Squalus Catulus { Haae-Gcelen ), Gunner., Trondh. Selsk. Skr., 
vol. II, p. 235; Ascan. ( Rodhaae ), Icon. Her. Nat., tab. 
XXXVIII; Risso, Ichtli. Nice , p. 30 (p. p. ; feminam Scyllio- 
rliini caniculce credidit); Lillj. ( Pristiurus ), Sv . , Norg. Fna , 
Fisk., vol. Ill, p. 657. 
Galeus melastornus, Rafin., Caratteri N. Gen., N. Sp., p. 13; 
Yarr., Brit. Fish., vol. II, ed. 1, p. 375 ( Scyllium ), ed. 
2, p. 495 {Pristiurus)', Bonap. {Pristiurus melanostomus ), 
Fna Ital., Pesci, tab. 131, fig. 3; Mull., Hle, Plagiost., 
p. 15, tab. 7; Lowe, Fish. Madeira, p. 93, tab. XIV; 
Kr. {Scyllium melastomum ), Danm. Fisk., vol. Ill, p. 832; 
Gthr {Pristiurus melanostomus), Gat. Brit. Mus ., Fish., vol. 
VIII, p. 406; Coll., Forh. Vid. Sels. Chrnia 1874, Tillasgsh., 
p. 211; N. Mag. Naturv., Bd 29 (1884), p. 117; Malm, 
Gbgs , Boh. Fna, p. 623; Winth., Naturli. Tidskr. Kbhvn, 
ser. 3, vol. XII, p. 58; Mor., Hist. Nat. Poiss. Fr., tom. 
I, p. 284; Day, Fish. Gt. Brit., Irel., vol. II, p. 314, 
tab. CLX, fig. 1; Storm, N. Vid. Sels. Skr. 1883, Trondhj., 
p. 43. 
Scyllium Artedi, Risso, Fur. Merid ., tom. Ill, p. 117; Barb. 
Boc., Cap. {Pristiurus), Peix. Plagiost., p. 11. 
Squalus annulatus , Nilss., Prodr. Ichthyol. Scand., p. 114; 
{Scyllium), Skand. Fna, Fisk., p. 713. 
The Black-mouthed Dog-fish attains according to 
Storm a length of 80 cm., according to Moreau of 90 
cm.; but it is commonly smaller. Our specimens from 
Scandinavia measure between 33 and 68 cm. The largest 
are females. The body is of the elongated Shark-form, 
with flattened snout, more terete, though somewhat de- 
pressed head, behind which the vertical section is more 
or less triangular (hog-backed), and more or less com- 
pressed tail, almost flattened on the sides, the depth 
just in front of the caudal fin being about twice the 
thickness. The greatest depth, at the pectoral fins, is 
in the males about 9 %, in the females about 10V 2 
of the length of the body. The greatest breadth falls 
within the head, just in front of the first branchial 
aperture, and varies, as usual, with the distension of 
the jaws and branchial apertures, being somewhat less 
Fig. 334. Ventral side of a Black-mouthed Dog-fish {Pristiurus ca- 
tulus), 9) from the fishing-bank of Jaderen. Nat. size. The anterior 
outer lobe {lae) of the right nostril is raised to show the anterior 
inner {lai) and the posterior outer {Ipe) lobes. 
or greater than the greatest depth. The least depth 
of the tail, just, in front of the caudal fin, is about 
4 — 4 x / 2 % of the length of the body. 
