228 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [4] 



The subdivision of the flounders into genera leaves room for consid- 

 erable variety of opiniou. Most of the species are well defined and 

 easily recognized, but they do not fall readily into generic groups unless 

 we regard almost every well-marked species as the type of a distinct 

 genus. A natural result of an attempt at sharply defining the genera 

 is to reach what seems an extreme degree of generic subdivision. On 

 the other hand, attempts to unite these smaller groups to form larger 

 ones often leave these larger ones at once unnatural and ill-defined. 



It will probably appear to some that the process of generic subdi- 

 vision has been in this paper carried too far. It is possible that this is 

 true, but the arrangement which we have adopted seems to bring out 

 the relations of the different forms better than can be done by a more 

 " conservative" view of the genera. For those who would reduce the 

 number of groups we suggest the following list of genera as represent- 

 ing a not unnatural mode of arrangement. 



I. — HlPPOGLOSSIX.E. 



Atheresthes. 



Platysomatk hthys. 



HlPPOGLOSSUS. 



i Lyopsetta. 

 HlPPOGLOSSOIDES < Eopsetta. 



' Hippoglonsoides. 



PSETTICHTIIYS. 



HlPPOGLOSSIXAJ^ ^ 088 ^' 



( Aystreurys. 



Pahaliciithys 



ParalioTithys. 



Ancylopsetia. 



II. — PlEURONECTIDjE, 



Phryxorhomius. 



Zeugopterus. 



Lepidoriiombus. 



ClTHARUS. 



( Bothus. 

 Pleuronectes < D7 



Arnoglossus. 

 Platophrys. 



ClTHARICHTIIYS 



MONOLEXE. 



PLEUROXICHTIIYS -> 



Hypsopsetta 



ISOPSETTA. 



C Syacium. 

 I Orthopsetta. 

 j Cilharichlhys. 

 \ Asevia. 

 I Etropus. 

 y Thysanopsetta. 



III. — Platessix.e. 

 Pleuronichthys. 



