122. PLEURONECTIDiE. 813 



process. Eyes very large, longer than snout, 3 J in head; maxillary 



extending to below posterior edge of pupil. Pectorals inserted above 



ventrals and below first ray of dorsal, which is strong, comiiressed, 



and armed anteriorlj' vvith sharp teeth directed upward; vent under 



last ray of first dorsal. Scales small, rough, but not keeled. Head 4; 



depth 5^. First D. 11; A. ca. 110; V. 8. Banks of Newfoundland to 



Norway, in deep water. 



{Coryphccnoidcs rupestris Guunor, Troiidhj. Selsk. Skrift. iii, 50, 1765: Coryphcbnoides 

 norvegicus Giiather, iv, 396: Maerourus norvegicus Nilssou, Skand. Fauuti Fiske 600, 

 1832: Maerourus stromi Roinh. Dausk. Vulensk. Afhandl. vii, 129.) 



Order U -HETEROSOMATA. 



{The Flat-fishes.) 



"Cranium posteriorly normal; anteriorly with twisted vertex, to allow 

 two orbits on the same side, or one vertical and one lateral; basis cranii 

 not quite simple. Dorsal fin long, of jointed rays. Superior i^haryn- 

 geals 4, the third longest, much extended forward, the inferior sepa- 

 rate." {Cope.) This order includes the single family of Pleuronectidce. 

 {srspo:;, different; cw.aa, body.) 



{AnacanthUii pleuronectoidei Giiutber, iv, 399-504.) 



Family CXXII and CXXIII.— PLEURONECTIDCE. 



{The Flounders.) 



Body strongly compressed, oval or elliptical in outline; head unsym- 

 metrical, the cranium twisted, both eyes being on the same side of the 

 body, which is liorizontal in life, the eyed side being uppermost and 

 colored, the blind side lowermost and usually plain. In very young 

 fishes the bones of the head are symmetrical, one eye on each side, and 

 the body vertical in the water. In some species the cranium becomes 

 twisted, bringing the upper eye over with it; in others the upper eye 

 moves through the cranium. Mouth small or large, the dentition 

 various; premaxillaries protractile; no supplemental maxillary bone; 

 pseudobranchiai present. Gills 4, a slit behind the fourth; lower pha- 

 ryngeals separate; no air-bladder; vent not far behind head. Scales 

 various, rarely absent, usually small. Lateral line usually present, 

 extending on the caudal fin, sometimes duplicated or wanting. Dorsal 

 fin long, continuous, of soft rays only, beginning on the head; anal 



