230 FISHES. 



to retain the ova. There is a dorsal with few, but elevated rays near the 

 nape; another very small one on the origin of the tail, and a large point- 

 ed caudal; otherwise they closely resemble Hippocampus. 



Only a single species is known, the Fistularia paradoxa, Pall., 

 Spic. VIII, iv, 6; it inhabits the Indian Ocean. 



Pegasus, Lin. 



The Pegases have a salient snout, formed, as in the preceding divi- 

 sions, but the mouth, instead of being at its extremity, is under its base; 

 it reminds us, by its protractility, of that of a Sturgeon, but is composed 

 of the same bones as in ordinary fishes. The body is mailed like that 

 of a Hippocampus and Solenostomus, but the trunk is broad and de- 

 pressed, the branchial apertures are on the side, and there are two distinct 

 ventrals behind the pectorals, which are frequently large, whence the 

 name of the genus. The dorsal and anal are opposite to each other. 

 The intestine, being lodged in a cavity wider and shorter than that of the 

 Syngnathi, has two or three flexures. 



Some species are found in the Indian Ocean*. 



After describing the five orders of osseous or fibrous Fishes, with com- 

 plete and free jaws, we pass on to the sixth order, or that of the 



ORDER VI. 



PLECTOGNATHES (a), 



"Which may be approximated to the Chondropterygii, with which it is 

 allied slightly by the imperfection of the jaws, and by the slow process of 

 the hardening of the skeleton ; this skeleton, however, is fibrous, and 

 generally its whole structure is that of ordinary fishes. The chief dis- 

 tinguishing character of the order consists in the maxillary bone being 

 soldered or permanently attached to the side of the intermaxillary, which 

 alone constitutes the jaw, and in the mode in which the palatine arch is 

 united by a suture to the cranium, and consequently having no power of 

 motion. Besides this, the opercula and rays are concealed under a thick 

 skin, through which only a small branchial fissure is visible +. Of ribs, 

 nothing is to be found but very small vestiges. There are no true ven- 



* Pegasus draco, L., Bl. 209;— Pegas. nutans, Bl. 121; — Peg. volans, L.;—P. la- 

 ternarius, Cuv., whose snout is furnished with six longitudinal rows of dentations. 



t This peculiar arrangement, indications of which are visible in the Chironectes, 

 has led several naturalists to believe that both opercula and rays are wanting in the 

 Plectognathes, but they are provided with them like other fishes. 



(it) From the Greek, pkho, to join as in a knot, gnatlws, the jaw. 



