so VERTEBRATE ANIMALS OF THE UNITED STATES 



0. mordax (Mitchill) . American smelt. Length 300 mm.; head 4; 

 depth 6.5; color greenish above, with dark dots; sides silvery; rays of 

 dorsal fin 10; anal 15; scales 68; mouth large, lower jaw projecting: 

 Atlantic Ocean from Virginia to Labrador, ascending the streams in the 

 winter to spawn in immense numbers; common in Lake Champlain and 

 other lakes; often landlocked; an important food fish. 



0. thaleichthys Ayres. Length 200 mm.; head 4.5;' depth 5.5; color 

 olivaceous; rays of dorsal fin 9; anal 14; scales 55 to 58: Pacific Ocean 

 from San Francisco to Alaska, ascending the streams in February. 



Order 2. Enchelycephali. — Body very elongate, cylindrical, with 

 minute imbedded scales or none; ventral fins wanting; anterior vertebras 

 distinct, without Weberian ossicles; premaxillaries atrophied or absent; 

 maxillaries lateral; air bladder, if present, with pneumatic duct; 

 opercular and pharyngeal bones more or less deficient; fins without 

 spines; gill-openings small; pseudobranchiae absent: 10 families, the 

 species being mostly marine and tropical; i species in the United States. 



Family Anguillidae. — Eels. Body very elongate, compressed 

 behind; head conical; mouth large, with projecting jaws; operculum 

 present; dorsal and anal fins confluent with the caudal; scales minute, 

 imbedded and hidden; lateral line present: i genus, with 4 or 5 species, 

 which occur in fresh, salt and brackish water in all parts of the world 

 except the Pacific coasts of North America and the islands of the 

 Pacific. American eels breed in the ocean between the West Indies and 

 Bermuda, and die soon after. Spawning may also occur in fresh water. 

 The young eels are very different in appearance from their parents and 

 are called Leptocephali. During the second spring the young eels ascend 

 the streams to feed in fresh water, in which they live several years. 

 When they are full grown they descend the streams to the sea; their 

 reproductive glands, however, do not mature for several weeks. Eels 

 eat fishes, crustaceans and carrion, and are voracious feeders. They 

 often travel considerable distances on land, through wet grass. 



Anguilla Shaw. With the characters of the family: several species, 

 I in America. 



A. rostrata (LeSueur). Common eel. Length 1,500 mm. or less; 

 weight up to 7 lbs.; color brown, often yellowish, paler beneath; head 

 8.5; depth 12 to 17: Atlantic Ocean, from Greenland to Brazil; also in 

 the West Indies; ascending all the rivers east of the Rockies; not found 

 in the Great Lakes above Niagara Falls or the upper Mississippi Valley, 

 unless introduced. 



Order 3. Eventognathi. — The suckers and carps. Anterior 

 vertebne modified, with Weberian ossicles; fins soft-rayed, being with- 



