and free at its extremity ; the mandible with cutaneous folds between its limbs at the 

 chin. Gill-opening extending above the opercular angle or at least above the pectoral. 

 The lower eye more anterior than the upper one, and the nostrils distant from the 

 jaws, that of the blind side being near the dorsal edge. 



Solea, in which the jaws are covered with scales, the superior one not fully 

 developed, and the scaly mandible not showing the usual folds at the chin. Gill- 

 openings wholly below the pectorals. The inferior eye farther back than the superior 

 one. Nostrils on both sides near the jaws. All the fin-rays divided, no spine in the 

 anal. (Richardson's Yarrell, Vol. I., p. 608.) 



In the "Regne Animal," first edition, 1817, Cuvier makes the Linnasan genus into 

 a family, which he calls simply " poissons plats," and divides it into genera and species 

 as follows : 



Platessa, including the plaice, Platessa platessa ; the flounder, Plaiessa flesus ; the 

 dab, Platessa limanda. 



Hippoglossus. including the PI. hippoglossus of Linnseus, and several species of the 

 Mediterranean described by other authors. 



Rhombus, including Rhombus maximus, the turbot and the brill, the PL nudus of 

 "Risso (apparently an Arnoglossus), and other species in which the upper eye 

 is at a great distance above and behind the lower. 



Solea, including the common sole, PL solea, Lin., the Pole of Belon, the Solea 

 oculata of Hondelet, the Pegouse of Eisso, and the lascaris and theophilus of 

 the same author. Also certain foreign species in which the vertical fins are 

 continuous, PL zebra, Bloch, PL plagusia, Lin. (These species now form the 

 genus Plagusia.} 



The Monochires, in which the right pectoral is very small, and the left minute 

 or altogether wanting, e.g., Linguatula, Eondelet, and the Achires, which have 

 no pectorals at all, are mentioned apparently as subgenera. Those Achires in 

 which the vertical fins are continuous with the caudal are distinguished as 

 Plagusia. 



The definition of Solea given by Cuvier is as follows : 



" Their peculiar character is that the mouth is twisted and as it were monstrous on 

 the side opposite to the eyes, and furnished on that side only with slender teeth closely 

 crowded together like the pile of velvet, while the side where the eyes are has no teeth. 

 Their form is oblong, their snout round and always projecting beyond the mouth ; the 

 dorsal fin commencing over the mouth, and extending like the anal up to the caudal. 

 Their lateral line is straight ; the side of the head opposite to the eyes is generally 

 furnished with a sort of villosity. Their intestine is long, with several convolutions, 

 and without caeca." 



It is evident that this definition of the genus admits of but little improvement. 

 Cuvier obviously meant the Monochires, Achires, and Plagusia to be mere subgenera 



