FISHES 51 



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 jaw; operculum pres- 

 ent; 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 are 

 important food fishes. 



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

 I in America. 



A. chrisypa Rafinesque {A. rostrata LeSueur). Common eel. 

 Length 1,500 mm. or less; weight up to 7 lbs.; color brown, often yellow- 

 ish, paler beneath; head 7; depth 12 to 17: Atlantic Ocean, from 

 Newfoundland to Mexico; 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 verte- 

 brae modified, with Weberian ossicles; fins soft-rayed, being without 

 spines; ventral fins abdominal; no adipose fin; lower pharyngeals 

 falciform, parallel with the gill-arches; maxillaries perfect; jaws tooth- 

 less; no pyloric caeca; air bladder with pneumatic duct: 2 very large 

 families of fresh water fishes. 



Key to Families of Eventognathi 



ai Lips usually thick and fleshy; dorsal rays with more than 10 rays. i. CatostomidcE. 

 ao Lips thin; dorsal fin with less than 10 rays 2. Cyprinidce. 



Family i. Catostomidae. — Suckers; mullets. Fishes of medium 

 size, with an elongate, more or less compressed body covered with 



