258 FISHES. 



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

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

 delicious. [X. maculosa., (Les.) Cuv. L. conijwessa, 

 (Les.) and JL. brosmiaoia., Storer. L. inornata^ DeK., 

 etc.] The common European species (X. mdgaris., 

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

 maculosa, is the older. 



SUB - OEDER. - HEMIBE A:^0H1. 



{The Half-Oilled Fishes.) 



FAMILY XCVIII.-GASTEROSTEID^. 



{The SticJdebacks.) 

 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 Cotiidce, 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 cceca. 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. 



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

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



Gastehosteus, 1. 



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

 serrated. 



:}::): 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. 



