258 FISHES. 



abundant; rather rare in the Miss. Valley. A curious fish, 

 rarely used for food, although the livers are said to be 

 delicious. \L. maculosa, (Les.) Cuv. L. compressa, 

 (Les.) and L. brosmiana, Storer. L. inornata, DeK., 

 etc.] The common European species (L. vulgaris^ 

 Cuv.) seems to be the same, but the American name, 

 lacustris, is the older. 



SUB - OEDEE. - HEMIBE ANGH1. 



(The Half-Oilled Fishes.) 



FAMILY XCVIIL-GASTEROSTEIDJE. 



(The Sticklebacks) 



Small fishes with the body elongated and compressed; 

 caudal peduncle very slender; mouth large, with the cleft 

 oblique; villiform teeth on jaws and pharyngeals; bran- 

 chiostegals three; opercles unarmed; sub-orbital bone 

 articulated with the preopercle (as in Cottidce, with 

 which these fishes were formerly associated) ; skin naked 

 or with bony plates; dorsal preceded by two or more 

 isolated spines; ventrals abdominal, of a stout spine, 

 accompanied by a rudimentary ray; air bladder simple; 

 a few pyloric caeca. Genera about five; species twenty- 

 five or less, in fresh waters and arms of the sea in north- 

 ern Europe and America. 

 * Dorsal with 2 to 6 free spines. 



t Sides mailed ; a serrated bony ventral cuirass and usually a 

 bony caudal keel ; dorsal spines not in a right line. 



GASTEROSTEUS, 1. 

 ft Sides naked; no caudal keel; ventral cuirass reduced, not 



serrated. 



ft Dorsal spines not in a right line when erected, the anterior 

 ones highest; ventral plates 2 not on median line, 

 caudal peduncle very slender. , . APELTES, 2. 



