8 



at the throat. Dorsal fin commencing on the snout in front of the eyes, 

 and not continuous with caudal. Nearly all the rays of the dorsal and 

 anal simple and undivided. Scales somewhat large, easily detached, 

 ctenoid. Lateral line with a rectangular bight above the pectoral. 



Arnoglossus megastoma (Megrim at Plymouth). Teeth on the vomer. 

 Anterior dorsal rays united by membrane for half of their length. The 

 base of the dorsal fin not passing on to the lower side of the head 

 anteriorly. Anterior nostril of the lower side protected by a broad flap 

 of flexible membrane. Eyes very large. Scales not so deciduous as in 

 the following species. Snout pointed. 



Arnoglossus laterna (Scald-fish or Scald-back at Plymouth). No teeth 

 on the vomer. Anterior dorsal rays free and separate ; the membrane 

 of the rest of the fin very slight, the rays easily becoming separate. 

 The anterior rays of the dorsal fin arise from the lower surface of 

 the head. Eyes not very large. Snout somewhat blunt. The base of 

 the left pelvic fin extends from the throat to the anus, and behind it 

 are one or two prominent spines. The four anterior rays of the dorsal 

 fin are very thick and much elongated in the male, not in the female. 

 Arnoglossus lophotes, Giinther, is the male. 



B. Eyes on the right side. 



I. Mouth terminal and large, teeth on both sides. 



1. Hippoglossus. Shape lanceolate ; dorsal fin commencing above the dorsal 



eye ; scales cycloid. Lateral line with a slight curve anteriorly. 

 Hippoglossus vulgaris, the Halibut. 



2. Hippoglossoides. Anterior end not much narrowed ; dorsal and ventral 



edges rather straight ; scales ctenoid. Lateral line straight. 

 Hippoglossoides limandoides, the Long Eough Dab. 



n. Mouth terminal and extremely small ; teeth most developed on the lower 

 side. 



1. Pleuronectes. Dorsal fin commencing above the dorsal eye ; eyes large 

 and prominent ; scales small or rudimentary. 



Pleuronectes platessa, the Plaice. Bony tubercles on the interorbital 

 ridge. Bright red spots ; scales uniform. Lateral line nearly straight. 



Pleuronectes microcephalus, the Merry- sole or Lemon-sole. Skin slimy. 

 Lateral line with a very small anterior curve. Colours mottled with a 

 good deal of yellow ; scales cycloid. Shape somewhat rectangular. 



Pleuronectes cynoglossus, the Pole-flounder or Witch. Shape elongated; 

 dorsal and ventral edges very gradually curved. Lateral line straight. 



