The Flounders 



aa. Ventral fins unsymmetrical, dissimilar in position and usually 

 also in form, the one on the eyed side being extended along 

 the ridge of the abdomen; eyes and colour on left side; 



Turbot tribe, 532 



ANALYSIS OF GENERA OF THE HIPPOGLOSSIN^E, OR HALIBUT TRIBE 



a. Vertebrae and fin-rays much increased in number; D. about 100; 



A. 85; caudal fin lunate. 



b. Large teeth in both jaws arrow-shaped, biserial, some of them 



depressible; upper eye with a vertical range; gillrakers short; 



Atheresthes, 522 



bb. Large teeth not arrow-shaped, biserial above, uniserial below; 

 gillrakers long and slender. 



c. Lateral line without anterior arch; lower pharyngeal teeth uni- 



serial ; Reinhardtius, 522 



cc. Lateral line with an anterior arch; lower pharyngeal teeth 



biserial ; Hippoglossiis, 523 



aa. Vertebrae and fin-rays in moderate number; D. fewer than 95; 



A. fewer than 75. 



d. Lateral line without distinct anterior arch. Species of sub- 



arctic distribution. 



e. Lateral line simple, without accessory dorsal branch. 

 /. Teeth in upper jaw biserial. 



g. Scales comparatively large, thin and deciduous; lateral line 70; 



Lyopseita, 524 



gg. Scales small and adherent; lateral line 96; Eopsetta, 524 



ff. Teeth in the upper jaw uniserial; Hippoglossoides, 525 



ee. Lateral line with an accessory dorsal branch; Psettichthys, 525 



dd. Lateral line with an arch in front. Species chiefly of temper- 

 ate or subtropical seas; Paralichthys, 526 



ANALYSIS OF GENERA OF THE PLEURONECTIN/E, OR FLOUNDER TRIBE 



a. Lateral line with a distinct arch in front; Limanda, 528 



aa. Lateral line without a distinct arch in front. 



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



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



female; lower pharyngeals very large, more or less united; 



Li op sett a, 53 1 

 cc. Scales all in both sexes and on both sides of body represented 



by coarse, scattered stellate tubercles; Platichthys, 531 



bb. Scales regularly imbricated, all ctenoid in both sexes: 



Pseudopleuronectes, 528 



521 



