CHONDROPTERYGII. 



583 



tians, Bichir, and is said to be one the best of the Nilotic fishes 

 for the table. The back has a long row of finlets. (See Chart.) 



The ALLIGATOR-GAR, Lepidosteus, (Gr. lepis, scale; osteon, 

 bone ) is confined to North America. The scales are smooth and 

 of adamantine hardness; the upper jaws consist of many 

 pieces. (Plate XIV. fig. 9.) 



The BUFFALO BONY PIKE, L. bison, is sometimes three feet in 

 length. 



The FLAT-NOSED BONY PIKE, L.- platyrhynchus, (Gr. broad- 

 snout,) is two feet in length, and found in Florida and the West 

 ern rivers. 



PLACOIDS. (Gr. M%, plax, a plate or tablet.) Plate-like scales. 



CARTILAGINOUS FISHES. CHONDROPTERYGII, (Gr. cartilage. 

 winged.) 



The skeleton in these fishes is not entirely destitute of calca 

 reous matter, but this is arranged in separate grains, and does 

 not form fibres or plates. The gelatinous substance, which in 

 other fishes, fills the intervals of the vertebra, and communicates 

 from one to other by a small hole, forms in several genera of 

 this division, a continuous cord, which perforates them all. 



FIRST ORDER. ELEUTHEROPOMI, (Gr. etevOegog, ekutheros, free ; 

 ,, pdma, cover.) 



The fishes of this order have pectinated or comb-like gills, 

 which are free, as in ordinary fishes, with one large external 

 opening on each side, furnished with a strong operculum or 

 cover ; they are without rays ; the upper jaw, formed by the 

 palatial bone, is firmly united to the maxillary ; the intermaxil 

 lary bone is rudimentary. 



(32) Chim&amp;lt;zridce, (Gr. diimaira, fabulous monster,) SEA- 

 MONSTERS. 



These are so called from the fantastic shape of the head, 

 which has a singular hoe-shaped appendage, tipped with spines 

 upon the snout. The second dorsal fin extends to the tip of the 

 tail, which is drawn out into a long slender filament. The eggs 

 are large, coriaceous, and have flattened hairy margins ; these 

 are esteemed by the Norwegians, who use them mixed up with 

 their pastry. The only species of the genus Chimcera, viz : C. 

 monslrosa, is abundant in the Arctic seas. (See Chart.) 



(33) Sturionida. The STURGEONS. 



These fishes have the body covered by hard bony tubercles or 



