BON/TO — DOLPHINS — FLAT-FISHES AND DORY 



347 



coasts and also off Tasmania, although it is most systematically fished in the 

 Mediterranean. Tunnies grow to a huge size, unusually large examples weighing 

 nearly half a ton. Their beef-like flesh is conspicuous in Italian fish-markets. 

 Closely allied is the bonito (T. pelamys), a species inhabiting all tropical seas, 

 where it may often be seen in pursuit of the shoals of flying-fish; but it also 

 ranges in the North Atlantic to the coasts of Scotland and Norway. Much the 

 same may be said with regard to the belted bonito (T. sardus), distinguished by 

 the presence of dark bands on the blue ground of the upper-parts. 



Here may be noticed an interesting type of scombroid fish from Argentine 

 waters named Chenogaster holmbergi, which is a member of the same group as 

 the New Zealand Lepidothynmus and Gasterochisma. From the New Zealand 

 forms Chenogaster differs by the united dorsal fins, while it is distinguished 



MACKEREL. 



from Gasterochisma by the small pelvic fins and from Lepidothynnus by the 

 presence of vomerine teeth. The three genera represent a circumpolar Antarctic 

 group. 



To the same section belong the large pelagic predatory fishes of 

 the family Coryphamidce and the genus Coryphama, popularly 

 miscalled " dolphins." Both of the two species, which grow to about six feet in 

 length, accompany bonito in the pursuit of flying-fishes. They may be recognised 

 by the deep, short-snouted head, and the long, slender body, terminating in a 

 deeply forked tail. 



nat-Fishesj The flat-fishes, which were formerly placed next the cod tribe, 



and Dory. are now regarded as specialised members of the spiny-finned group, 

 nearly related to the John Dory (Zeus faber). These Pletironectida}, as they are 

 called, inhabit all temperate and tropical seas, the species from the tropics being 

 characterised, as a rule, by the brilliancy of their colouring. Among the Indo- 

 Pacific genera of these fishes are Pseudorhombus and Rhomboidichtliys, both of 

 which have the eyes on the left side, the latter being also characterised by the 



