86 
SCANDINAVIAN FISHES. 
THE SCAD OR HORSE-MACKEREL (sw. taggmakrilen). 
CARANX TRACHURUS. 
Plate V, fig. 3. 
The lateral line proper covered along its whole length with transverse plates, which, on the posterior part of the 
line , which is straight and longer than the anterior part , which is curved, are keeled and posteriorly f urnished with 
% of the length of the body and greater than the greatest depth of the 
of its length. No finlets behind the dorsal or anal fin. 
a spine. Length of the head about 2 
body , 'which is about 22 
l 
29—32“ 
A. 2/ 
1 
27 -29 b 
; P. 2 + 17 1. 18; 
V. V.; C. *+16 1. 17+*; L. hit. 73—75+ 
jSyn. — ctiooQ , Aristot. ; Tgayovgog , ^Elian.: vide Artedi. 
Scomber linea laterali aculeata, pinna ani ossiculorum 30, Art., 
Gen., p. 31; Syn., p. 50. 
Scomber Trachurus, Lin., Syst. Nat., ed. X, tom. I, p. 298; Hetz., 
Fn. Suec. Lin., p. 340; Lacep. ( Car ana : ) Hist. Nat. Poiss., 
vol. Ill, p. 57 et 60; Cuv., Val., ( Trachurus ) Hist. Nat. 
Poiss., vol. IX, p. 11, tab. 246; Ivr0y. ( Garanx ) Damn 
Fiske, I, p. 263; Ekstr., Gbgs Vet., Vitt. Samb. Handl 
1850, p. 37; Id. (cum Weight) Stand. Fiskar, ed. I, p 
221, tab. 57; Malm, Ofve.rs. Vet.-Akad. Fork. 1852, p. 226; 
Nilss., Stand. Fn., Fisk., p. 152; Gthr ( Trachurus ) Cat 
Brit. Mus., Fish., vol. II, p. 419; Steind. ( Garanx ) Stzber 
Akad. Wiss. Wien., Math. Naturw. Cl., Bd. LVII, Abth. 1 
(1868) p. 382; Coll., Vid. Selsk. Forb. Christ. 1874, Til- 
lsegsh., p. 50; Id. ibid. 1879, p. 32; Cederstr., Ofvers. 
Vet.-Akad. Forb. 1876, N:r 4, p. 64; Winth. Naturh. Tidskr. 
Kbhvn., ser. Ill, vol. XII, p. 15; Id., Zool. Dan., Fiske, 
p. 19, tab. IV, fig. 1 ; Day, Fish., G:t Brit., Irel., I, p. 
124, tab. XLIV ; Lillj., Sv ., Norg. Fisk., I, p. 330; Mob. 
u. Heincke, Fisclie der Ost-See, p. 37. 
Trachurus sauries, Raein., Caratteri cli Alcuni Nuovi Generi 
(1810) p. 20; Jord., Gilb., Syn. Fish. TV. Amer. Bull. U. 
S. Nat. Mus., N:r 16, p. 912; Brown-Goode, Fisher. In- 
dus tr. U. S., part. I, p. 326, tab. 103. 
Garanx semispinosus , Nilss., Prodr. Ichth. Scand., p. 84. 
Trachurus Linnei, Malm, Gbgs, Boh. Fn., p. 421; Lute., 
Spot. Ail., Vid. Selsk. Skr. Kbhvn. ser. V, Naturv. Mathem. 
Afd., XII ( 6 ), p. 533. 
The usual size of the Scad in the Cattegat is from 
27 to 30 cm. The largest Ekstrom ever saw measured 
395 mm. from the tip of the snout to the end of the 
middle rays of the caudal fin. The body is fusiform, an 
intermediate form between that of the common Mackerel 
and the Perch, somewhat compressed and so deep that 
the greatest depth, which is half way along the first 
dorsal fin, is about 22 % or 23 % of the length of the 
body. The greatest thickness, measured at the same 
point, is about half the greatest depth. The back is 
broad and rounded up to about the middle of the se- 
“ Exceptionally 33 — 35, according to Steindachner. 
b 25 — 30 
tt ■" J ^ “ 1 tt tt tt 
c 70 — 79 
It i i V , ,, ,, ,, 
c.ond dorsal fin, as is also the front part of the belly. 
On the belly from the insertion of the .ventral fins to 
the vent, there is a groove into which the ventral fins 
may sink, and behind that another which contains the 
vent together with the two spines before the anal fin 
and the anterior part of that fin. A similar groove, 
in which the first dorsal fin and the anterior part of 
the second may be hidden, runs along the back. The 
head is of average size, cuneiform and so strongly 
compressed underneath that the branches of the lower 
jaw and the two interopercula touch below the isthmus. 
The length of the head is from 26'5 % to 27‘5 % of the 
length of the body. The forehead is rounded with a 
narrow, filiform carina (the outward sign of the supra- 
occipital ridge) in the middle. It slopes towards the 
snout in a curve continued by that of the back. The 
snout is blunt and the mouth of average size. The 
lower jaw is the longer; its articulation, which forms 
an obtuse angle, is situated somewhat behind the an- 
terior margin of the eye, and its length is equal to 
the distance between the tip of the snout and the po- 
sterior margin of the pupil. Fine teeth, which are 
scarcely distinguishable, are set in both jaws, on the 
tongue, on the wide head and the shaft of the vomer 
and on the palatine bones. The eyes are large and 
set high. Their vertical diameter is from 24 % to 22 % 
of the length of the head. The nostrils are nearer the 
eyes than the snout. Of the bones of the gill-cover 
the preoperculum is the largest: its margin is smooth 
and rounded at the corner. The operculum is small and 
triangular, with a crescent-shaped incision in the posterior 
margin, which is filled by a membrane, on which we 
find the large black spot so common in this genus. The 
gill-openings are large. The branchiostegal membranes 
are free, but that on one side of the body is united 
