238 "PERFECT-MOUTHED" FISHES 



more extraordinary ; they appear to consist of a gigantic head, 

 behind which the dorsal and ventral fins stand out like paddles. 

 They frequent the open sea, sometimes descending to great depths, 

 at other times slowly swimming near the surface with the high 

 dorsal fin above the water. The Trunk-fishes, that live in shallow 

 water of the tropical seas, resemble nothing so much as a roughly 

 carved head of a cow. These fishes are encased in a box-like 

 cuirass formed of hexagonal horny plates ; two large horns project 

 forward over the large round eyes, and behind this grotesque- 

 looking object the tail fin stands out like a fan. 



Better known is the Sea-horse (Hippocampus), of the Mediter- 

 ranean Sea, with its curious head shaped like a knight's head in 

 a set of chessmen, and long, prehensile tail. This quaint little 

 fish floats through the water in an upright position, steering its 

 way along with its small pectoral fins. It is fond of coiling its 

 tail round pieces of seaweed or other floating objects, and allowing 

 itself to drift idly with the current. The body of the Sea-horse 

 is encased in bony plates, and its eyes can be moved independently 

 of each other in the same way as the eyes of a chameleon. The 

 male carries its eggs and young in a brood pouch under the tail 

 in the same manner as many of the pipe-fishes, to which family 

 the little sea-horse belongs. The sea-horse has a fairly wide dis- 

 tribution, and species are not infrequent on the south coast of 

 England. 



Another curious Mediterranean fish, of a different type, is the 

 John Dory (Zeus faber). Its body is very compressed, and the 

 spines on the first dorsal fin are produced into long tendril-like 

 filaments. The skin is almost scaleless, olive brown in colour, 

 with changing lights of gold, blue, and white, and on each side 

 it bears a large black spot surrounded by a lighter ring. Its mouth 

 is telescopic, and can be thrust out to seize prey, which it has a 

 curious manner of securing. 1 " It does not overtake it by superior 

 speed like the mackerel, or lie in wait for it like the angler-fish, but 

 stalks it and approaches it by stealth. It is able to do this in 

 consequence of the extreme thinness of its body and the peculiar 

 movement of its hinder dorsal and ventral fins. The dory places 

 itself end on towards the fish it desires to devour, and in this posi- 

 tion it is evident it excites no alarm on the part of its prey. The 



1 Cunningham. 



