SCOMBRID^E. 93 



Genus II.— Orcynus {Cuvier), Liithen. 



Branchiostegals seven : pseudobranchiai present. Body oblong and somewhat 

 compressed. Cleft of mouth deep. Small teeth on the jaws, vomer and palatine 

 bones, none on the tongue. Two dorsal fins, the spines of the first weak : finlets 

 posterior to the second dorsal and anal fins : no free spine before the anal Jin. Scales 

 small, covering the body, those on the anterior portion of the body forming a species 

 of corselet. Lateral-line unarmed, a longitudinal heel along either side of the free 

 portion of the tail. Air-bladder, when present, simple. Pyloric appendages numerous. 



Geographical distribution. — Found in most tropical and temperate seas. 



Fishes of this genus differ from the true mackerel, Scomber, in having a 

 longitudinal keel along either side of the free portion of the tail, and the two 

 dorsal fins being placed close together : while the corselet, which is commencing 

 to be seen in Scomber colias, becomes now more developed in adults, and the 

 pectoral fins are likewise elongated in examples which have attained to their full 

 growth. 



They are very voracious, and may be seen in shoals pursuing other fish on 

 which they prey. 



As food, they frequently occasion indigestion and diarrhoea when eaten fresh, 

 but are more digestible when salted or otherwise prepared. 



Davy in his " Physiological Researches," obseives that he found the heat of 

 the body of a tunny considerably higher than that of the surrounding water, 

 caused by the quantity of red particles in its blood. 



1. Orcynus thynnus, Plate XXXV. 



Ovi'voq, Aristot. ii, c. 13, iv, c. 10, v, c. 9-11, vi, c. 17, viii, c. 2, 12, 13, 15, 19, 

 30, is, c. 2 ; ^Elian, is, c. 42, xiii, c. 13, 16, 27, xv.'c. 3,5,6; Athen. vii, pp. 122, 

 301, 316, 319 ; Oppian, Hal. ii, p. 48, iii, 620. Opwvos, Lilian, i, c. 40 ; Oppian, 

 i, c. 8, ii, p. 59 ; Athen. vii, pp. 301. 315. MeXctVopue, Athen. vii, p. 315. Thunnus, 

 Ovid, Hal. v, p. 98. Thynnus, Pliny, is, c. 15 ; Strabo, Geogr. iii, p. 145, v, p. 

 223, and vii, p. 320 A. sii, p. 345 D. xvii, p. 834. Orcynus, Pliny, xxxii, c. 11 ; 

 (icsner, p. 962, and Ed. 1598, f. 59, c. fig.; Aldrov. iii, c. 18, p. 314; Jonston, 

 lib. i, t. 1, c. 2, Art. 1, t. iii, f. 4 ; Rondel, viii, c. 13, p. 249, c. fig. Melandrys, 

 Pliny, is, c. 15. Thunnus sive Thynnus, Belon. p. 108; Rondel, p. 241. Tonno, 

 Salv" p. 123. Thynnus, Gesner, pp. 957, 967, 1148. Tunny fish, Willughby, p. 

 1 76, pi. M. 1, f . 3 ; Ray, p. 58. Thunnus, Schonev. p. 75. Scomber, Briinn. Pise. 

 Mass. p. 70, n. 86. Tunny, Pennant, Brit. Zool. (Ed. 1) iii, p. 266, pi. Iii, (Ed. 2) 

 iii, p. 360, pi. lxiii. Scomber, No. 2, Artedi, Genera, p. 31 ; Duhamel, ii, Sect. 7, 

 c. 2 ; Cetti, Stor. Nat. di Sard, iii, p. 138 ; Laquat, Voy. p. 23. 



Scomber thynnus, Linn. Syst. i, p. 493 ; Gronov. Zooph. No. 305 ; Bloch, t. Iv; 

 Gmel. Linn. p. 1330; Lacep. ii, p. 605; Bl. Schn. p. 21 ; Bonaterre, Ency. Ich. 

 p. 139, pi. lviii, f. 228; Shaw, Zool. iv, p. 581; Donovan, Brit. Fish, i, pi. v; 

 Turton, p. 101 ; Risso, Ich. Nice, p. 163 ; Scouler, Mag. Nat. Hist. 1833, vi, p. 529 ; 

 Fleming, p. 218; Jenyns, p. 362; Martens, Reise nach Venedig. ii, p. 432. 



Thynnus mediterraneits, Risso, Eur. Merid. iii, p. 414 ; Collett, Norges Fiske, 

 p. 44. 



Tlnpnnts riilqnri.t, Cuv. and Val. viii, p. 58, pi. ccs ; Yarrell, Brit. Fish. (Ed. 1) 

 i, p. 138, c. fig. (Ed. 2; i, p. 150 (Ed. 3) ii, p. 209 ; Cuvier, Regne Anim. 111. Poiss. 

 pi. xlv, f. 2 ; Storer, Fish. Mass. p. 47 ; Swainson, Fishes, ii. p. 238; Thompson, 

 Ann. Nat. Hist, v, p. 9, and Nat. Hist. Ireland, iv, p. 94; De Kay, New York 

 l;i una, Fishes, p. 105, pi. x, f. 28; Guichen. Explor. Sc. Alger. Poiss. p. 57; 

 Steind. Ich. Span. u. Port. 1868, p. 7. 



Thynnus Orientalis, Tern, and Schleg. Fauna Japon. p. 94. 



Orcynus secundi-dorsalis (Storer) Gill. Amer. Fish. Report, 1873, p. 802. 



Thynnus thynnus, AYhite. Calal. Brit. Fish. p. 30; Gunther, Catal. ii, p. 362, 

 and Fische Godefroy Mus. Heft. v. December , 1876, p. 150. 



