284 FLATFISHES (HI-;TFR0S0:MATA) 



J Vertebra' 40 to 45 ; dorsal 67-101, anal 51-79 : body not elongate ; 



caudal peduncle not slender ; caudal never lunate ; teeth pointed. 



(I. Interorbital space an obtuse ridge ; supratemporal branch of 



lateral line, if present, without posterior prolongation ; dorsal 



origin above eye. anterior rays not free. 



a. Teeth in upper jaw uniseriaj. 



* All pectoral rays generally simple ; dorsal origin above 



anterior part of eye ; upper eye completely lateral ; snout 

 and eye-balls not scaled ... 4. Hippoglossoides. 

 ** Middle rays of pectoral branched ; dorsal origin above middle 

 or posterior part of eye. 

 t Upper eye completely lateral ; snout and upper surfaces 



of eye-balls densely scaled . . 5. Acanthopsetta. 



tt Upper eye with vertical range ; snout more or less scaled ; 



eye-balls not scaled . . .6. Cleisthenes. 



/3. Teeth in upper jaw biserial. 



* Scales of moderate size, deciduous ; all pectoral rays simple ; 



jaws without distinct canines ... 7. Lyop.sktta. 



** Scales small, adherent ; middle rays of pectoral branched ; 



jaws with canines anteriorly ... 8. Eopsktt.\. 



/), Interorbital space flat ; supratemporal branch of lateral line with 



a long posterior prolongation ; dorsal origin in front of eye. 



anterior rays a little prolonged, more or less free from membrane ; 



teeth in upper jaw uniserial ; middle rays of pectoral branched 



9. PSETTICHTHYS. 



B. Maxillary scarcely J head ; jaws rather stronger on blind side, but 

 dentition nearly equally developed on both sides ; teeth obtusely 

 conical, biserial above, uniserial below .... 10. Verasper. 



II. Mouth smaller, maxillary on ocular side less than J head ; jaws and dentition 

 better developed on blind side. 

 A. Maxillary on blind side nearly J head ; teeth stout, conical, in two 

 distinct rows in both jaws ; scales of ocular side (in adults) all replaced 

 by rough tubercles ; blind side quite naked . . .11. Cliiiouerma. 



n. Maxillary on blind side not more than J head. 



1 . Teeth small, acute, in villiform bands ; supratemporal branch of 



lateral line with a long posterior prolongation ; lower pharyngeals 



narrow, scarcely approximated ; scales all cycloid. 

 a. Lips simple ; dorsal origin on median line of head 12. Hypsopsetta. 



h. Lips thick, with transverse plica; ; dor.sal origin on blind side of 



head ....... 13. Pleuronichthys. 



2. Teeth larger, obtuse, conical or incisor-hke. uniserial or .sometimes 



irregularly biserial. 

 a. Pyloric appendages well developed, generally of moderate length 

 or rather long, 2 t0 4 -f i to 5 ; lower pharyngeals generally narrow, 

 the inner edges usually evenly curved and scarcely approximated 

 (e.xcept in Pleuronectes). the teeth generally in two rows. 

 <i. Supratemporal branch of lateral line with a posterior prolonga- 

 tion. 



* Lateral line with low curve above pectoral 



t Scales of ocular side strongly ctenoid ; eyes rather small, 



upper lateral ; teeth conical ... 14. Isopsetta, 



tt Scales of ocular side mostly cycloid ; eyes large, upper 

 with nearly vertical range ; teeth with truncated tips 



15. Parophrys 

 ** Lateral line with high curve above pectoral 16. Lepidopsetta. 



