DISTRIBUTION AND LOCATION 273 



coast of America, and others from Hawaii to India and in 

 Japan. Diodon hystrix is found in tropical seas all round the 

 world, other species are more limited in their range. The flesh 

 of all the Gymnodonts is poisonous. The well-known Sun- 

 fishes, although very different in shape, belong to the division 

 Gymnodonts ; they are rather pelagic than littoral though often 

 found near the coast ; they extend also into temperate regions, 

 the common sun-fish {Orthagoviscus mold) being frequently 

 taken off the British coasts. It is known to feed on larval 

 fishes and is said to eat also jelly-fishes. Professor Grass i found 

 larval eels in its stomach in the Straits of Messina, and believed 

 these were swallowed at great depths, although it is usually 

 seen swimming slowly at the surface. This species is cosmo- 

 politan, while the short sun-fish, Ranzania truncata, is found 

 in the Atlantic and Mediterranean and another species of the 

 genus in the Pacihc. 



The Pomacentridae are short stout-bodied fishes allied to 

 the wrasses which are common on our own shores. (Frontispiece, 

 A.) The wrasses or Labridas themselves are likewise tropical 

 and most of them brilliantly coloured, but they also extend into 

 temperate regions ; they live in the neighbourhood of rocks and 

 sea-weed. The Scaridae, or parrot-wrasses, which are able, by 

 means of their strong beak, to prey upon corals, are most 

 abundant in the tropical Pacific, but there are nine species in 

 the Atlantic, one of which is common in the Mediterranean. 



Numerous other Acanthopterygians occur on tropical coasts, 

 as the Serranidae or sea-perches, Sciaenidae, Gerridae and Pristi- 

 pomatidae, Mullidae or red mullets and Callionymidae or dra- 

 gonets. Gadidae are entirely absent, with the exception of a 

 little pelagic form, Bregmaceros, which occurs in the Pacific but 

 not in the Atlantic. Flat-fishes, on the other hand, are well 

 represented, but by special genera, mostly belonging to the sub- 

 families of sole-like or turbot-like forms. Of Malacopterygii, 

 Clupeidae are abundant, the tarpons, Elops, Megalops, A//w/a, 

 and numerous species of Muraenidae occur. The characteristic 

 Elasmobranchs are Scylliidae only among the Selachii ; of the 

 Batoidei, Pristidae, saw-fishes, the Rhinobatidae, Trygonidre, 

 sting-rays and Myliobatidae eagle-rays. 



In the Arctic regions the number of species is very small 

 and forms a marked contrast with the large number in the 



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