LOPHOBRANCHII. 
327 
intestine is of uniform width, and without coeca; and their air-bladder, though slender, is 
large in proportion to their size. They form two genera ; and the first admits of subdivision. 
SyngnaiJms. — These are characterized by a tubular snout, composed, as in the Fistularidae, of pro- 
longations of the ethmoid, vomer, temporals, pre-operculum, and other bones ; and this snout ends in a 
mouth as in other fishes, only its opening is nearly vertical. The gill-opening is near the nape ; and 
there are no ventral fins. In their reproduction there is this peculiarity, that the eggs slide into a 
pouch formed by an inflation of the skin, and remain there till they are hatched. This pouch is under 
the belly in some, and at the base of the tail in others. It bursts spontaneously, and allows the fry to 
escape. [Thus these fishes have some analogy to the marsupial Mammalia.] 
I Syngnathus, the Pipe-fishes, properly so called, have a very long and slender body, differing little in diameter 
] throughout its entire length. Some have a dorsal, caudal, and anal ; others want the anal only, and in these the 
i hatching-pouch is situated under the tail. S. acus, the Great Pipe-fish, and S. tylphe, the Peak-nosed Pipe-fish, 
both found in the British Seas, belong to these sections. Others, again, have neither anal nor pectorals ; and 
^ others no fin but the dorsal. S. ophidion, the Snake Pipe-fish, and S. lumbriciformis, the Worm Pipe-fish, are 
] British fishes belonging to these sections. [They have the pouch under the belly ; and it is to be observed that in 
all the species it is the male, and not the female, which has the pouch, and hatches the eggs.] 
Hippocampus y has the body compressed laterally, and much more elevated than the tail ; and in dead speci- 
! mens the neck bends, and the upper part has a faint resemblance to the head and neck of a Horse in miniature, 
from which they have been called Sea-horses. The margins of their scales are formed into ridges, and the angles 
I into spines. They have no fin in the tail, but that organ is prehensile, and enables them to climb or hold on by 
the stalks of marine plants. The common species is found in the British seas, and is sometimes about five inches 
long ; and, on the coast of Australia, there is a longer one, with the angles of the scales extended into leafy 
i appendages. 
i Solenostomus, differ from the former chiefly in having, behind the pectorals, large ventrals united with each 
' other and with the body, and forming an apron which serves to retain the eggs while hatching, in the same 
manner as the pouch of the Pipe-fishes. There is one dorsal of few rays near the nape, a very small one near the 
ii tail, and a large pointed caudal, but otherwise they resemble Hippocampus. The only known species is from the 
ji Indian Ocean. 
;j Pegasus, have a snout as in the former, but the mouth under it, and moveable, like that of a Sturgeon, only 
i composed of the same bones as in other osseous fishes. The body is armed as in Hippocampus, but their thorax 
i is broad, depressed, and with the gill-openings in the sides. They have two distinct ventrals in rear of the pecto- 
ij rals, which are often large, and have procured these fishes the name of Pegasus, or Flying Horses, The dorsal 
[j and anal fins are opposite each other, the abdominal cavity is wider and shorter than in Syngnathus, and the in- 
! testine has two or three flexures. Some species are found in the Indian seas. 
I THE SIXTH ORDER OF BONY FISHES. 
! PLECTOGNATHI (Fishes with Soldered Jaws). 
ij Though retaining many of the characters of the Bony Fishes, the members of this order re- 
I semble the Cartilaginous ones, in the imperfect structure of the jaws, and the slow ossification 
, of the skeleton ; but still this skeleton is fibrous, and resembles that of the Bony Fishes. The 
I chief characters are — the maxillary soldered to the side of the intermaxillary, which consti- 
i tutes the jaw, and the connexion of the palatal arch with the cranium by an immoveable 
suture. Besides, the gill-lid and rays are concealed under the thick skin, with only a small 
! opening, the ribs are mere rivets, and there are no true ventrals. The intestine is large, and 
I without coeca ; and the air-bladder is always ample. They admit of division, by the character 
i| of their teeth, into two very natural families, 
Jl THE FIRST FAMILY OF THE PLECTOGNATHI. 
i; 
i! Gymnodontes (Fishes with naked Teeth). 
I Instead of teeth, these have the jaws covered with a substance hke ivory, laminated internally, and 
1 resembling the beak of a Parrot, though these are true teeth united, and are reproduced as soon as they 
I are destroyed by using. Their gill-lids are small, with five obscure rays. They live on Crustacea and 
sea-weed, and their flesh is mucous, and not hked, — that of some species being reckoned poisonous, at 
I xcast at certain seasons of the year. 
