Jordan and Evermann, Fishes of North America. 2607 



II. PLEURONECTIN^E. 



*H 



(FLOUNDER TRIBE.) 



Mouth small, uusymmetrical, the jaws on the eyed side with nearly 

 straight outline, the bones on the blind side strongly curved; dentition 

 chiefly developed on the blind side; eyes large; edge of preopercle not 

 hidden by the scales; pectoral fins well developed; vertical fins well 

 separated; ventral fins nearly or quite symmetrical, that of the eyed side 

 not prolonged along the ridge of the abdomen ; anal spine usually strong 

 (obsolete in Microstomus and Embassichthys). Body dextral (except fre- 

 quently in Platichthys stellatus) . Species arctic or subarctic in distribution. 



a. Vertebrae in moderate number, from 10 + 26=36 to 11 + 33 = 44; dorsal rays 65 to 



80; anal rays 45 to 60. 



b. Teeth small, acute, in several series ; lateral line nearly straight, with an acces- 

 sory dorsal branch ; lower pharyngeals narrow, with small biserial teeth ; 

 scales cycloid. 



c. Lips thick, each with several longitudinal folds; dorsal fin beginning on 

 the blind side; vertebra} 38 to 40. PLEURONICHTHYS, 1029. 



cc. Lips simple ; dorsal fin beginning on the median line ; vertebra) (in H. gut- 

 tvlata) 11 + 24 = 35. HYPSOPSETTA, 1030. 



bb. Teeth chiefly uniserial, all more or less blunt, conical or incisor-like. 

 d. Lateral line with an accessory dorsal branch. 

 e. Lateral line without distinct arch in front. 

 /. Teeth compressed, incisor-like, close set. 



g. Scales closely imbricated, mostly cycloid; upper eye on 

 median line; vertebrae (in P.vetulus) 11 + 33=44. 



PAROPHRYS, 1031. 



gg. Scales scarcely imbricated, all very strongly ctenoid ; eyes 

 both lateral. INOPSETTA, 1032. 



ff. Teeth conical, separated, not incisor-like ; scales closely imbri- 

 cated, all strongly ctenoid; mouth comparatively large (ap- 

 proaching that of Psettichthys) ; vertebrae (in I. isolepis) 10+ 

 32 = 42. ISOPSETTA, 1033 . 



ee. Lateral line with a distinct arch in front ; scales imbricated, rough - 

 ctenoid; vertebra) (in L.bilineata) 11 + 29=40. 



LEPIDOPSETTA, 1034. 

 dd. Lateral line without accessory dorsal branch. 



h. Lateral line with a distinct arch in front; scales imbricated, rough- 

 ctenoid ; vertebra) (in L. limanda) about 40. LIMANDA, 1035. 

 hh. Lateral line without distinct arch in front. 



i. Scales regularly imbricate, all (on eyed sidej ctenoid in both 

 sexes ; no stellate tubercles on head nor on bases of dorsal 

 and anal fins; teeth, incisor-like, close set; lower pharyn- 

 geals very narrow, each with 2 rows of separate, conical 

 teeth ; fin rays scaly. PSEUDOPLECEONECTES, 1036. 



ii. Scales imperfectly imbricated, or else not all ctenoid. 



j. Scales chiefly cycloid in both sexes ; lower pharyngeals 

 small and narrow, separate, each Avith about 1 row of 

 small, bluntish teeth; teeth incisor-like, close set, 

 forming a cutting edge; no stellate scales at base of 

 dorsal and anal. PLEURONECTES, 1037. 



jj. Scales rough-ctenoid in the male, more or less cycloid in 

 the female (fin rays scaly in the male, naked in the 

 female) ; lower pharyngeals very large, more or less 

 united in the adult, their surface somewhat concave, 

 the teeth in 5 or 6 rows, large, blunt, close set; teeth 

 in jaws incisor-like; fin rays of dorsal and anal with- 

 out tubercles at base. LIOPSETTA, 1038. 



