228 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [4] 
The subdivision of the flounders into genera leaves room for consid- 
erable variety of opinion. 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 
cumber of groups we suggest the following list of genera as represent- 
ing a not unnatural mode of arrangement. 
J.—HIPPOGLOSSIN A. 
ATHERESTHES. 
PLATYSOMATICHTHYS. 
HIPPOGLOSSUS. 
'¢ Lyopsetta. 
Hirroctossonnes) Hopsetta. 
Hippoglossoides. 
PSETTICHTHYS. 
Hrerocuossina § Zimpogiossina. 
t Xystreurys. 
Paralichthys. 
PARALICHTHYS ‘ 
Ancylopsetta. 
JI.—PLEURONECTIDA. 
PHRYNORHOMBUS. 
ZEUGOPTERUS. 
LEPIDORHOMBUS. 
CITHARUS. 
Bothus. 
PLEURONECTES 
Pleuronectes. 
ARNOGLOSSUS. 
PLATOPHRYS. 
( Syacium. 
Orthopsetta. 
| Citharichthys. 
Azevia. 
Etropus. 
 Thysanopsetta, 
CITHARICHTHYS 4 
MONOLENE. 
III.—PLATESSIN&. 
Pleuronichthys. 
PLEURONICHTHYS ; Hypsopsetta. 
ISOPSETTA. 
= 
