ACANTHOPTERYGII. 143 



detached, forming what are termed false or spurious fins, or pinnas 

 spurise. The genus is subdivided as follows: 



Scomber, Cuv. 



The Mackerels have a fusiform body covered with uniformly small 

 and smooth scales; two little cutaneous crests on the sides of the 

 tail; an empty space between the first and second dorsal. 



Sc. scombrus, L., Bl. 54. (The Common Mackerel.) Blue 

 back, varied with black undulating streaks; five false fins above 

 and beneath. The value, 8cc. of this fish is too well known to 

 need a comment. The Common Mackerel has no natatory blad- 

 der; but, and it is a singular fact, that organ is found in several 

 other species, so similar to it, that some attention is necessary 

 to distinguish them; such are the little Mediterranean Mackerel^ 

 Sc. colias; Sc. pneumatophorus, Laroche, Ann. Mus., XIII; and 

 the Sc. grex, Mitch., Ann. New York Lye, I, 423, which is 

 sometimes seen on the coast of the United States, in countless 

 numbers, Ecc, (l) 



Thynnus, Cuv. 



A soft corslet round the thorax, formed by scales larger and 

 smoother than those on the rest of the body; a cartilaginous carina 

 between the two little crests on the sides of the tail; the first dorsal 

 extends close to the second, 



Sc. thynnus, L. (The Tunny.) This fish has been taken in the 

 Mediterranean, from a very ancient date, and by its abundance 

 constitutes a great source of wealth to Provence, Sardinia, Si- 

 cily, See. It is said to attain the length of fifteen and eighteen 

 feet, and has nine spurious fins above, and as many beneath; the 

 pectorals are one-fifth of its whole length. Several neighbour- 

 ing species inhabit the Mediterranean, that have hitherto been 

 but badly distinguished. 



Sc. brachypteriis, Cuv.; the Alicorti, Rondel., 245, and Duham., 

 Sect. VII, pi. vii, f. 5. Pectorals but one-eighth of the whole 

 length. 



Sc. thunina, Cuv.; La Tonine; Aldrov., 315; Descrip. de 

 I'Eg. Poiss. pi. xxiv, f. 5. A brilliant blue marked with black 

 lines, undulated and curved in various ways, Sec. It is also in 

 this first group that we must place the 



(1) \dd. Scomber vemalis, Mitch, loc. cit; — Sc. canagurta, Cuv., Russ , 136. 

 Vol. II.— T 



