EQUATORIAL ZONE. 273 



Tropic, or appear in single species only ; and of Teleosteans, 

 the Berycidcc, Pagrus, the Heterohpiclina, Cottus and allied 

 genera, Lophius, Anarrhichas, Stichoeus, Lepadogaster, Psy~ 

 chrolutes,Centriscus,Notacanthus,t\\Q Lcibridce and Embiotocidm, 

 the Lycodidm, Gadidm, and marine Salmonidm disappear 

 either entirely, or retire from the shores and surface into the 

 depths of the ocean. 



With regard to variety of forms, as well as to number 

 of individuals, tliis zone far surpasses either of the tem- 

 perate zones ; in this respect, the life in the sea is as that 

 on the land. Coast fishes are not confined to the actual 

 coast-line, but abound on the coral reefs, with which some 

 parts of the Atlantic and Pacific are studded, and many of 

 which are submerged below the water. The abundance of 

 animal and vegetable life which flourishes on them renders 

 them the favourite pasture-grounds for the endless variety of 

 coral-fishes (Squamipinnes, Acronurida3, Pomacentridcc, Julidcc, 

 Plectognathi, etc.), and for the larger predatory kinds. The 

 colours and grotesque forms of the Fishes of the Tropics have 

 justly excited the admiration of the earliest observers. Scarlet, 

 black, blue, pink, red, yellow, etc., are arranged in patterns 

 of the most bizarre fashion, mingling in spots, lines, bands ; 

 and reminding us of the words of Captain Cook when de- 

 scribing the coral-reefs of Palmerston Island : " The glowing 

 appearance of the MoUusks was still inferior to that of the 

 multitude of fishes that glided gently along, seemingly with 

 the most perfect security. The colours of the different sorts 

 were the most beautiful that can be imagined — the yellow, 

 blue, red, black, etc., far exceeding anything that art can 

 produce. Their various forms, also, contributed to increase 

 the richness of this sub-marine grotto, which could not be 

 surveyed without a pleasing transport." 



Of Chondropterygians the Scylliidm, Pristis (Saw-fishes). 

 Bhindbatidce, and Trygonidce attain to the greatest de- 



T 



