[39] | FLOUNDERS AND SOLES. 263 
TYPE: Rhombus ocellatus Agassiz. 
This well-marked genus is widely diffused im the warm seas. The 
sexual differences are greater than usual among flounders, and the dif- 
ferent sexes have often been taken for different species. As a rule, in 
the males the pectoral fin of the left side is much prolonged, the inter- 
orbital area is much widened and very concave, and there are some 
tubercles about the snout and lower eye. The young fishes, as is usually 
the case, resemble the adult females. This genus has been generally 
called Rhomboidichthys, but the appropriate name, Platophrys, is earlier, 
as Bleeker bas already noticed. 
Lately Dr. Emery has shown that the larval flounder, known n as Peloria 
heckelt, is in all probability the young of Pleuronectes podas. 
The generic name Coccolus, based on forms slightly more mature than 
those called Peloria, probably belongs here also. 
We have seen no larval forms so young as those which have been 
described as Peloria heckeli. We have, however, examined smail trans- 
parent flounders, one with the eyes quite symmetrical, taken in the Gulf 
Stream, and another with the eyes on the left side, taken at Key West. 
Both these may be larvee of Platophrys oceliatus. The figures published 
by Emery seem to make it almost certain that the corresponding Euro- 
pean forms belong to P. podas, although some doubt as to this is ex- 
pressed by Facciola. 
The species of Platophrys are widely distributed through the warm 
seas, no tropical waters being wholly without them. The group called 
Engyprosopon seems to be worthy of generic distinction from Platophrys, 
as its scales are large and rough ctenoid. All the known species of 
Engyprosopon are Asiatic. 
All the species of Platophrys are extremely closely related and can 
be distinguished with difficulty. On the other hand the variations due 
to differences of age and sex are greater than in any other of our_ 
genera. 
A species apparently belonging to Platophrys has been scantily de- 
seribed by Schneider (Systema Ichthyologia, 1801, 156) under the name 
of Pleuronectes surinamensis. His types were small, smooth individu- 
als (“exampla satis parva et glabra”), with the fins scaly, the mouth 
small, the lateral line arched in front, and the dorsal rays 96, the anal 
rays 55. These may be the young of any of the West Indian species, 
possibly of P. lunatus or ocellatus. 
The following analysis of the species of Platophrys will doubtless be 
found tobe very unsatisfactory. There are certainly three species (podas, 
maculifer, and lunatus) which are known to be distinct in their adult 
state. The young forms of maculifer and lunatus are not well known, 
nor is it known how they differ from ocellatus, spinosus, and other species 
which presumably reach a smaller size. Only a thorough study of the 
species, in all stages of development, in their native waters can give us 
the characters by which the species can be really discriminated. 
