[7] FLOUNDERS AND SOLES 231 



g. Lateral line simple (without accessory dorsal branch) ; teeth sharp, 

 those of lower jaw uniserial; dorsal beginning above eye. 

 h. Teeth in the upper jaw biserial. 

 i. Scales comparatively large, thin, and deciduous (lateral line 70) ; body 

 slender, the flesh soft ; vertebra; (exilis) 11+34—45. 



Lyopsetta, 4. 

 ii. Scales small and adherent (lateral line 96) ; body robust, the flesh 



firm; vertebra; (jordani) 114-32=43 Eopsetta,5. 



hh. Teeth in the upper jaw uniserial ; scales small and flesh firm ; vertebra; 



(platessoides) 13-j 32=45 Hippoglossoides, 6. 



gg. Lateral line with an accessory dorsal branch ; vertebrae 40 to 42 ; scales 

 small, firm, ctenoid ; dorsal fiu beginning before the eye ; teeth 

 sharp, unequal, some of them canine-like; mouth not large; 

 lower pharyngeal teeth sharp, uniserial ; vertebra; (melanost ictus) 



11+29=40 PSETTICHTHYS, 7. 



ff. Lateral line with a strong arch in front ; no accessory branch ; vertebra; in 

 smaller number (35 to 41); teeth uniserial; anal spine usually 

 obsolete ; body normally sinistral.* (Species chiefly of the tem- 

 perate or sub-tropical seas, none of them Arctic and none Euro- 

 pean.) (Genera allied to Paralichthys.) 



k. Dorsal fin beginning above the pupil ; gill-rakers short and thick ; teeth 

 rather small; no canines; body indifferently dextral or sinis- 

 tral (in some species at least). 



I. Scales ctenoid Hippoglossixa, 8. 



II. Scales cycloid ; caudal fin subsessile, the caudal peduncle extremely 



short ; skin of shoulder-girdle with patches of cup-shaped scales ; 

 vertebra; (liolepis) 12+25=37 Xystreukys, 9. 



kk. Dorsal fin beginning in advance of eye. 



m. Scales weakly ciliated; caudal fin with a distinct peduncle; teeth unequal, 

 some of the anterior canine-like ; gill-rakers rather long and 



slender; vertebra;, 35 to 41 Paralichthys, 10. 



mm. Scales very strongly ctenoid on both sides of body ; mouth small- 

 ish, with small, sharp teeth ; anterior rays of dorsal notably ex- 

 serted, the rays of the anterior part of the fin longer than some 

 of those further back, thus forming a more or less distinct lobe ; 

 gill membranes considerably united ; gill-rakers short and broad ; 

 caudal peduncle short ; left ventral produced ; vertebra; (quadro- 

 cellata) 9 + 26:= 35 Axcylopsetta, 11. 



Subfamily II.-PLEURONEOTINiE. 



(Large-mouthed flounders, with the central fins unsymmctrical.) 



Mouth symmetrical, the dentition nearly equally developed on both 

 sides ; gape usually wide (narrow in Platophrys, Etropus, etc.), the max- 

 illary commonly more than one-third length of head. Lower pharyn- 

 geals narrow, each with one or more rows or a narrow band of small, 

 sharp teeth; teeth in jaws acute. Eyes not minute ; pectorals and ven- 

 trals usually well developed. Edge of preopercle free. Ventral fins 

 dissimilar in form or in position, that of the left or eyed side inserted 

 on the ridge of the abdomen, its base extended along this ridge, its rays 

 more or less wide apart. Caudal fin rounded or subtruncate ; no ac- 



*Dextral in some species of Hippoglossina ; occasionally dextral in some species of 

 Paralichthys and Xystreurys. 



