TUNNY. 95 



corset appearing when recent from the water. Pectoral fin 

 slender, in a depression of the surface, eleven inches long, but 

 not reaching to the termination of the first dorsal fin; by which, 

 among other marks, it is distinguished from the Germon or 

 Long-finned Tunny. The corset line runs from the upper 

 margin of the pectoral fin, and in a waved form passes up to 

 the second dorsal; but before its rise the lateral line passes off 

 to the tail; at its termination a strong elevated ridge, with a 

 slight converging ridge above and below at the origin of the 

 tail. 



The first dorsal fin begins nearly above the origin of the 

 pectorals, with, in different specimens, thirteen and fourteen 

 firm rays; the first rays elevated, but becoming shorter as they 

 extend close to the second dorsal, and all of them received 

 into a chink. Second dorsal and anal not opposite, both hook 

 shaped, their substance too stout to allow of counting their 

 rays. Pectorals with thirty-two rays. Ventral fins strong, sunk 

 into a depression, with six flat rays. The number of false fins 

 differs in different examples; varying from ten to nine above, 

 and fi'om nine to eight below. The tail greatly incurved, and 

 slender towards the extremities; but the circle at the middle 

 is interrupted by a double projection, forming it into two fins, 

 with thirty rays. The tongue has a raised border or ridge on 

 each side, its colour black. Colour of the back, top of the 

 head, and jaws black, with a tint of blue, lighter at the sides; 

 the belly white. Finlets bright yellow. 



The physiological condition of the family of the Mackarel is 

 most highly developed in the Tunny, and is highly characteristic. 

 Its vessels are so filled with red blood, as to give the flesh 

 the appearance of beef; and in consequence of this abundance 

 of red particles in the circulating fluid, the heat of its body 

 was found by Dr. Davy to be considerably higher than that of 

 the sea, and of any other fishes he had an opportunity of 

 examining, and to maintain a vigorous circulation of this blood, 

 of which the high degree of heat is a cause and consequence, 

 we find the heart possessed of a well-marked and powerful 

 organization. It is large, firm, and in shape an irregular solid 

 triangle. Internally — there are cords which spring from that 

 portion of the auricle, (the office of which is to receive the 

 blood from the veins,) which is close to its union with the 



