SUCKING-FISHES. 371 



corselet on the anterior part of the body only, and the presence of only a single 

 longitudinal ridge on each side of the tail. The tunnies have a geographical 

 distribution coextensive with that of the family ; and in a fossil state are found 

 in the Eocene and Miocene deposits of the Continent. The common species, which 

 attains a length of over 10 feet, and a weight of half a ton, is an occasional visitor 

 to the British coasts, and is abundant in the Mediterranean, where it has been 

 regularly fished for since very early times. At the present day specimens of a 

 hundredweight each may often be seen in the Lisbon market ; their flesh, which 

 is as red as beef, being cut up and sold by weight. The bonito (T. pelamys) is a 

 smaller and more slender fish, rarely exceeding a yard in length, and frequenting 

 all temperate and tropical seas ; while the name of albicore is applied to species 

 like T. albicora of the Atlantic, characterised by the great length of their pectoral 

 fins, some of these fish attaining a length of 6 feet. Albicore and bonito will 

 follow in the wake of sailing-ships for weeks together. They prey largely on 

 flying-fish; and Bennett writes of one species that it was interesting "to mark 

 the precision with which it swam beneath the aeronaut, keeping him steadily in 

 view, and preparing to seize him at the moment of his descent. But this the flying- 

 fish would often elude by instantaneously renewing his leap, and not unfrequently 

 escape by extreme agility." Moseley writes that, when at St. Vincent, he saw a 

 tunny of some 25 Ibs. in weight attracted by baits thrown into the water by some 

 negroes, who kept on casting in fresh ones for some time, in order to give their 

 victim confidence. " A very strong piece of cord, with a hook like a salmon-gaff 

 made fast to it, was then baited with a small fish, just enough to cover the point 

 of the hook, and a stout bamboo used as a rod. The cord was hitched tight round 

 one end of it, with about a foot of it left dangling with the hook. One negro held 

 the rod, and another the cord, the bait being held just touching the surface of the 

 water. The fish swam up directly, and took it; the negro holding the bamboo 

 struck sharply, and drove the big hook right through the fish's upper jaw, and 

 both men caught hold of the line and pulled the fish straight out on to the rock." 

 This instance indicates the remarkable boldness and voracity of the tunnies, the 

 fish in question not being six feet distant from the negro holding the pole when 

 it took the bait. Passing over several allied genera, such as Pelamys and Cybium, 

 we proceed to a more interesting group of the family. 



The remarkable adhesive disc on the upper surface of the head 

 Sucking-Fishes. 



at once serves to distinguish the sucking-fishes, not only from their 



immediate relatives, but likewise from all other members of the class ; and it may 

 be mentioned that the development of this disc by means of what is called natural 

 selection presents one of the strongest , objections to the acceptance of that 

 doctrine, since in its incipient stages such a structure would be utterly useless. 

 The genus Echeneis, to which all the half-score species of sucking-fish pertain, 

 differs from all those noticed above in the absence of finlets ; the sucking-disc 

 being formed by a modification of the spines of the dorsal, and being composed 

 of a number of transverse plates, varying from twelve to twenty-seven, according 

 to the species. It is not a little remarkable that there exists in the Indian Seas, 

 as also in the Tropical Atlantic, a fish (Elacate nigra) closely allied to the sucking- 

 fishes, but with the disc represented by a few short and separated spines ; and it 



