86 



SCANDINAVIAN FISHES. 



THE SCAD OR HORSE-MACKEREL (.s\v. taggmakeilen). 



CAKANX TRACHURUS. 



Plate V, fig. 3. 



The lateral Ihic proper covered ulo)i(j its irhole length irith transverse plates, irhich, on the posterior part of the 



line, tchich is straight and longer than the anterior part, irliidi is carved, are keeled and posteriorlg furnished with 



a spine. Length of the head about 27 % of the length of the hodg and greater than the greatest depth of the 



body, which is about 22 % of its length. No finlets behind the dorsal or anal fin. 



V. 



R. Or. 7; D. 8/ 

 ,; C. ,r+lfi 1 



29—32" 

 1~ +j:; L. 



A. 2/- 

 hit 



'27—29*' 



73— 75^ 



P. 2 + 17 



18: 



^yn. ^aiQOc:, Aristot. ; TQoyovQog, jElian.: vide Aetedi. 



Scomber linea lateral! aculeata, pinna ani ossiculoriira 30, Art., 



Gen., p. 31; Si/ii., p. 50. 

 Scomber TracJuirtis, Lin., Syst. Nat., ed. X, torn. I, p. 298; Retz., 



Fn. Suec. Lin., p. 340; Lacep. (Caranx) Hist. Nat. Foiss., 



vol. Ill, p. 57 ct 60; Cuv., Val., (Trachurus) Hist. Nat. 



Foiss., vol. IX, p. 11, t.ib. 24G; Kroy. {Uaranx) Damn. 



Fiske, I, p. 263; Kkstr., Gbgs Vet., Vitt. Samli. Handl. 



1850, p. 37; Id. (cum Wright) Sk-and. Fislcar, ed. I, p. 



221, tab. 57; Malm, Ofvers. Vet.-Akad. Forli. 1852, p. 226; 



NiLss., Shmd. Fn., Fislc, p. 152; Gthr {Trnchurus) Cat. 



Brit. Mus., Fisb., vol. II, p. 419; Steind. (Caranx) Stzber. 



Akad. Wiss. Wien., Matb. Nadirw. CI., Bd. LVII, Abth. 1 



(1868) p. 382; Coll., Vid. Selsk. Forh. Christ. 1874, Til- 



litgsli., p. 50; Id. ibid. 1879, p. 32; Cederstr., Ofvers. 



Vet.-Akad. Forli. 1876, N:r 4, p. 64; Winth. Naturb. Tidskr. 



Kbbvn., ser. Ill, vol. XII, p. 15; Id., Zocl. Dan., Fiske, 



p. 19, tab. IV, tig. 1; Day, Fish., G:t Brit., Irel., I, p. 



124, tab. XLIV; LiLLJ., Sv., Norg. Fisk., I, p. 330; Mob. 



11. IIeincke, Fische der Ost-See, p. 37. 

 Trachurns sanrtis, Bafin., Caratteri di Alcuni Nitovi Generi 



(1810) p. 20; JoRD., Gild., Syn. Fish. N. A7ncr. Bull. U. 



S. Nat. Mus., N:r 16, p. 912; Brown-Goode, Fisher. In- 



ditstr. U. S., part. I, p. 326, tab. 103. 

 Varaii.r semispinosus, NiLSS., Prodr. Ichth. Hcand., p. 84. 

 Trachurus Liunei, Malm, Gbgs, Boh. Fn., p. 421; Lt)TK., 



Spol. Atl., Vid. Sclsk. Skr. Kbbvn. ser. V, Naturv. Matbem. 



Afd., Xll (6), p. 533. 



The usual size of the Scad in the Cattegat is from 

 27 to 30 cm. The lai'gest Eksthom ever saw measured 

 395 mm. from the tip of the snout to the end of the 

 middle raAs 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 wa}^ 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 hall' the greatest depth. The back is 

 broad and I'ounded up to about the middle of the se- 



cond 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 venti'al fins 

 may sink, and liehind that another which contains the 

 vent together ^vith the two spines before the anal fin 

 and the anterior part (if 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 l)lunt 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 hio-h. 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 preopereulum is the largest: its margin is smooth 

 and rounded at the corner. The operculum is small and 

 triangulai-, Avith a crescent-shaped incision in the posterior 

 margin, \vhich is filled by a membrane, on ^vhich -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 



" Exceptionally 33 — 35, according to Steindachner. 

 1) 25 32, „ ,, „ 



c 70 70 



