SYGNATHUS. GREAT PIPE-FISH. 275 



opens almost vertically. There are no ventral fin?, 

 and, in the majority of instances, no anal, pectoral, or 

 caudal. But the most remarkable peculiarity they 

 present is, in the genus Sygnathus, a marsupinl 

 pouch under the abdomen, in which the eggs are 

 matured, and into which it would appear the young 

 occasionally retreat. Although the section contain- 

 ing the species destitute of a caudal fin, and without 

 a marsupial bag, is sufficiently distinct from the 

 other to be distinguished generically, we do not 

 find that this has been done by any recent author 

 except Mr. Swainson ; but as the name Acus which 

 he applies is objectionable from being used in a spe- 

 cific sense in the same family, we have substituted 

 -another term of equivalent meaning. 



Gen. XCVII. Sygnathus.* — In this group, 

 which contains only two British species, the pecto- 

 ral, dorsal, anal, and caudal fins, are all present; 

 and the males are furnished with an elongated 

 pouch under the tail. 



(Sp. 203.) S. Acus. Great Pipe-fish. Attains 

 a length of between twelve and sixteen inches in 

 our seas, but in the Mediterranean and some other 

 seas seems to grow much larger. The body is 

 heptangular anteriorly, then becomes hexangular, 

 and the whole of the caudal portion is quadrangular. 

 The osseous plates which cover the body are about 

 sixty-three in number, all of them beautifully stri- 



* From 9V9 and ^vaSoj, jaws united ,- a name given by Ai> 

 tedi in tlie belief that the elongated muzzle of these fishes waa 

 formed b.v the union of their jaws. 



