1936] Schultz: Keys to Fishes 157 



Family 44. Pleuronectidae. 7 Halibuts and Flounders 



la. Mouth large, symmetrical, dentition of jaws equal on eyed and blind side 

 or nearly so ; length of maxillaries on eyed side contained fewer than 3 

 times in the head. (Hippoglossinac, subfamily, halibut tribe.) 



2a. Lateral line with either a distinct arch in front or an accessory dorsal 

 branch or both. Fig. 14. 



3a. Lateral line with a distinct arch in front, but without accessory dorsal 

 branch; anterior dorsal rays not elongate or fringe-like; dorsal rays 91 

 to 107; anal rays 69 to 80; vertebrae 49 to 51. Range: Japan, to Alas- 

 ka, to northern California. Marine. Abundant. 

 Pacific Halibut 132. Hippoglossus stcnolcpis Schmidt 



3b. Lateral line without distinct arch in front, but with accessory dorsal 

 branch; eyes small; interorbital space very wide; 1st 10 dorsal rays 

 elongated and fringe-like ; dorsal rays 72 to 85 ; anal 53 to 62 ; ver- 

 tebrae 37 to 39; scales about 112. Range: Alaska to Monterey. Ma- 

 rine. Common. 

 Sand Sole 133. Psettichthys melanostictiis Girard 



2b. Lateral line without distinct arch in front or accessory dorsal branch. 



4a. Mouth very large, the maxillary reaching to below the posterior mar- 

 gin of lower eye; teeth in jaws arrow-shaped in adults; dorsal rays 

 95 to 111; anal rays 81 to 99; scales about 135; vertebrae 47 to 49. 

 Range : Bering Sea to San Francisco. Marine. Common. 



Arrow-toothed Halibut 



134. Atheresthcs stomias (Jordan and Gilbert) 



4b. Mouth moderately large, the maxillary reaching only to about the 

 center of the orbit of the lower eye. 



5a. Upper jaw with a single series of small sharp conical teeth; scales 

 small, about 110 to 120 in the lateral line (88 to 92 pores); no 

 scales directly on lateral line ; dorsal rays 72 to 90 and anal 57 to 

 71 ; vertebrae 42 to 46 ; principle caudal rays 18. Range : Alaska to 

 Puget Sound. Marine. Common. 



Sole. Flathead. 135. Hippoglossoides elassodon Jordan and Gilbert 

 5b. Upper jaw with a double row of conical teeth. 



6a. Scales large, about 68 to 73 in the lateral line; scales located 

 directly upon lateral line contain pores ; dorsal rays 72 to 88 ; 

 anal 57 to 64; vertebrae 42 to 45. Range: Alaska to San Diego, 

 California. Marine. Common. 

 Rough Sole 136. Lyopsetta exilis (Jordan and Gilbert) 



6b. Scales small, about 88 to 100 along lateral line ; no scales lo- 

 cated directly upon the lateral line ; dorsal rays 87 to 101 ; anal 

 rays 67 to 79; vertebrae 41 to 44; principle caudal rays usually 

 19, seldom 18 or 20. Range: Puget Sound to San Diego Bay. 

 Marine. Common. 

 Sole. English Sole 137. Eopsctta jordani (Lockington) 



lb. Mouth asymmetrical, dentition and cleft extending much further on blind 

 side than on the eyed side ; total length of maxillaries on eyed side usually 

 contained more than 3 times in the head. (Pleuronectinae, subfamily ; floun- 

 der tribe). 



