2798 THE BONY FISHES AND GANOIDS 



which not only is there no pouch on the under surface of the males, but the body 

 is rounded and nearly smooth, and the caudal fin either rudimentary or want- 

 ing. All the pipefishes are carnivorous in their diet; and it is stated that in 

 those species provided with a pouch, the fry will return to this for shelter for 

 a considerable time after birth. The pipefishes swim about slowly in a very 

 peculiar manner, more generally vertically or in an inclined position than hor- 

 izontally, contorting their bodies into every conceivable kind of posture, and 

 poking their long snouts inquisitively into bunches of seaweed in their search 

 for food. 



The prehensile structure of the tail is the chief difference between sea horses 

 and pipefish, although in all the existing representatives of the former group there 

 is no caudal fin. The sea horses are divided into several genera, of which the typi- 

 cal one is best known by the short-snouted sea horse {Hippocampus antiquorum} , 

 ranging from the Atlantic and Mediterranean to Australia, and occasionally found 

 in the British seas. In this genus the body is more or less compressed and deep, 

 with its investing bony shields raised into tubercles or spines of variable length; 

 while the back of the head is compressed into a crest, terminating in a well-marked 

 knob. Small pectoral fins are present, and the males have a pouch beneath the tail, 

 with its aperture near the vent, in which to carry the eggs. The curious resem- 

 blance presented by the heads of these fishes to that of a horse has obviously given 

 rise to their popular name. They are represented by about a score of species. A 

 remarkable instance of resemblance to their natural surroundings is afforded by the 

 three representatives of an Australian genus of sea horses, one of which (Phyllo- 

 pteryx eques) is shown in the preceding illustration. In these fishes the body 

 may be either compressed or as broad as deep; some or all of its smooth bony plates 

 being furnished with long spine-like processes projecting from its edges, and many 

 of these terminating in irregular leaf-like appendages. There are a pair of spines 

 on the muzzle, and others above the eye; pectoral fins are present; and the tail is 

 about equal in length to the body. In the absence of a pouch, the eggs are em- 

 bedded in soft membranous skin on the under surface of the tail. These sea horses 

 closely resemble the color of the seaweeds to which they attach themselves, while 

 the filamentous appendages of their spines appear as if they were actually a part of 

 the vegetable growth. These species are of relatively -large size, attaining a length 

 of as much as a foot. 



FlLEFISHES AND COFFER FlSHES Family 



With the filefishes and their allies we come to the first of the two families 

 constituting the suborder Plectognathi, of which the following are the distinctive 

 characteristics: In the head the bones are completely ossified, while in the rest of 

 the skeleton they are incompletely hardened; the number of vertebrae being few. 

 The small gill openings are situated in front of the pectoral fins, and the gills them- 

 selves are pectinate; the mouth being narrow, with some of the bones of the upper 

 jaw united, and in certain cases both jaws prolonged to form a beak. There is gen- 



