206 DIVISION I. VERTEBRAL ANIMALS.—CLASS IV. PISCES. 
vestiges of rays are shown in the substance of the operculum. These fishes 
are also distinguished by shields, or small plates, which cover the body, and 
often give it an angular form.” 
There are two genera : — 
Synenaruus. — The Pipe-fishes. They have the tubular snout of the 
Fistularide. The gill-opening is near the nape, and there are no ventral 
fins. They have a striking analogy to the Marsupials, in the Class Mam- 
malia, in having a pouch under the belly in some, and at the base of the 
tail in others. The eggs slide into this pouch, which is formed by inflation 
of the skin, and remain there till they are hatched. There are several spe- 
cies, of which S. fuscus, the Brown Pipe-fish, and S. Peckianus, Peck’s 
Pipe-fish, are found in our waters. S. acus, the Great Pipe-fish, and 
S. ophidian, the Snake Pipe-fish, and some others, are foreign. These all 
have the pouch under the belly. In these fishes, the order of Nature, in 
regard to reproduction, seems to be reversed; for it is the male, and not 
the female, which has the pouch, and hatches the eves. 
Hippocampus. — The jaws of this group are like those of the preceding ; 
mouth placed at the end; the margins of the scales are formed into ridges, 
and the angles into spines. There is no fin in the tail, but that organ is 
prehensile, and enables the fish to climb or hold on by the stalks of marine 
plants. 
IT, Brevirostris. — The Short-nosed Sea-horse is sometimes found on our 
shores. It is about five inches long, and of a yellowish-brown color. 
BONY FISHES. ORDER VI. PLECTOGNATHI. 
This order is composed of those fishes which have the maxillary soldered 
to the side of the intermaxillary, which constitutes the jaw, and the palatal 
arch connected with the cranium by an immovable suture. The differences 
in the character of their teeth divide them naturally into two families. 
The First Family comprises the G'ymnodontes, i. e., fishes with naked 
teeth. They have the jaws covered with a substance like ivory, laminated 
internally, and resembling the beak of a parrot. This structure is really 
composed of teeth united, which are reproduced as soon as they are de- 
stroyed by using. They live on crustacea and sea-weed, and their flesh is 
mucous and inedible. 
Trrraopon. — Each jaw is marked with a suture, so as to give the ap- 
pearance of four teeth, and the spines are small and low. 
T. Turgidus. — The Swell-fish. This singular fish, which is common in 
Buzzard’s Bay and the Vineyard Sound, has the faculty of blowing itself 
