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Fishery Bulletin 96(4), 1998 
ily and only exclude Clidoderma from the fourth 
pleuronectid lineage. This species has 14 abdominal 
vertebrae found to be synapomorphic for Hippo- 
glossinae; it also has a thickened first anal 
pterygiophore suggesting a common ancestry with 
Hippoglossus and Verasper. A rounded caudal fin, 
observed in Verasper is also observed in Clidoderma. 
Phylogenetic position of this species could be further 
ascertained by an examination of the accessory pro- 
cesses on caudal vertebrae, the palatine structure, 
and the structure of gill rakers on first, second, and 
third epibranchials. 
Subfamily Eopsettinae The Eopsettinae consists of 
E. grigorjewi and E. jordani. This analysis defines 
this subfamily with two synapomorphies (Fig. 6): 
presence of gill rakers on fourth epibranchial (40); 
and a single row of teeth on lower jaw (41). Gill rak- 
ers on the fourth epibranchial are observed in 
Cleisthenes herzensteini, C. pinetorum (Hippo- 
glossoidinae), and Psettichthys melanostictus 
(Psettichthyini). The number of rows of teeth on the 
lower jaw were found to be much more homoplastic. 
The latter feature was also observed in Reinhardtius 
hippoglossoides , Verasper moseri, and V. variegatus 
(Hippoglossinae) as well as in many species of the 
Pleuronectinae. 
Genus Eopsetta This genus was described in 
Norman (1934) by a number of plesiomorphic char- 
acters. The presence of distinct canines on the upper 
jaw was suggested in Norman (1934) as diagnostic 
for Eopsetta. However, distribution of this character 
in the Pleuronectidae is not well defined. Members 
of the Hippoglossinae also have teeth of irregular 
lengths (16, Fig. 9A). The longer teeth can also be 
interpreted as canines in these species. From this 
analysis, data supporting monophyly of Eopsetta are 
not conclusive, but no other interpretation is avail- 
able owing to insufficient information. 
Subfamily Lyopsettinae 
Genus Lyopsetta This lineage contains only L. 
exilis. Its position as a monotypic lineage within the 
Pleuronectidae is determined by five derived char- 
acter states (Fig. 6): 12 to 14 abdominal vertebrae 
(23); barbed teeth present on dentaries and premax- 
illae (42); supratemporals on both ocular and blind 
sides are jointed at anterior ends of their bifurcation 
(43, 44, Fig. 13B); and presence of scales on eye sur- 
faces (45). 
These structures are also distributed within other 
pleuronectid taxa. An increase in abdominal verte- 
brae is found in Hippoglossinae, some species of 
Hippoglossoidinae, and in two separate lineages of 
Pleuronectinae. Barbed teeth are also observed in 
Reinhardtius. Bifurcation of the supratemporals is 
also observed in Reinhardtius hippoglossoides, 
Cleisthenes , Hippoglossoides , Glyptocephalus 
cynoglossus, G. stelleri, G. zachirus, Microstomus 
pacificus , Limanda aspera, and Pleuronectes 
platessus. Presence of scales on the eye surfaces is 
also found in Reinhardtius stomias, Acanthopsetta 
nadeshnyi, Dexistes rikuzenius, Glyptocephalus 
kitaharai, and Microstomus. The distribution of these 
character states within the family does not indicate 
an alternative hypothesis of relationships between 
Lyopsetta exilis and other pleuronectid taxa. 
Subfamily Hippoglossoidinae This subfamily con- 
tains seven species (6 examined) in three genera: 
Acanthopsetta, Cleisthenes, and Hippoglossoides. 
This group is characterized by four synapomorphies 
(Fig. 6): absence of supraoccipital plate extending 
posteroventrally between epiotics (46, Fig. 10B); 
pterosphenoid and prootic of blind side join to form 
dorsal margin of anterior prootic foramen (47, Fig. 
7, B and C); pterosphenoid of blind side is reduced 
and does not form posterior margin of orbit (48, Fig. 
7B), a reversal, except in Cleisthenes; and two uniform 
rows of teeth present on fifth ceratobranchial (49). 
