73 Part I11.—Twenty-fourth Annual Report 
The earstones of two other plaice, each about 456mm. long (not 
represented among the photographs), measured fully 65mm. in length by 
about 55mm. at their greatest width, and 9mm. by nearly 6mm., and 
thus agreeing fairly well with the others in their proportion to the length 
of the fishes they belonged to. 
On comparing the earstones of the smaller halibut with those of the 
larger specimens of long rough dabs and plaice, a certain similarity may 
be traced both in the general form of the otoliths and of their markings 
as well as in the proportion of the length to the depth (or width). It 
will be seen that they are all broadly oval in outline, their lower edge is 
evenly rounded, and the widest part of the otolith is apparently at the 
posterior end. The earstones of Pleuronectes flesus and Pleuronectes 
limanda, and of one or two others, are also somewhat similar in form to 
those referred to. There is, however, at least one notable exception in 
the Genus Pleuronectes, P. cynoglossus, or the Witch Sole, to be referred 
to presently, the earstones of which are nearly circular in outline instead 
of being oval. 
Pleuronectes microcephalus, Don. The Lemon Dab. Pl. i. B., figs. 
19-25. 
The earstones of the lemon dab are comparatively small and are not 
very distinctly characterised. Fig. 19 represents those of a fish 15 inches 
long, and they only -measure a little over 4mm. by about 2°5mm. To 
show how small these earstones are it is only necessary to mention that 
those of a long rough dab scarcely as large as this species had ear- 
stones nearly double their length, while the earstones of a plaice that was 
at least 4 inches shorter were one and a half times as long. In the 
annexed Table the sizes of several other lemon dabs are given whose 
earstones are represented by photographs on the accompanying plates. 
Earstones. 
Higure “i ne Size of the Fish. 
Length. Depth. 
20 12 inches. 3°5mm. 2‘Omm. 
21 izle 30mm. 1‘5mm. 
22, 62 ,, 28mm. 1‘5mm. 
23 5k ,, 2°‘5mm. 1-3mm. 
24 Ps 2‘Omm. 1‘Omm. fully. 
25 BE 95 1‘7mm. 10mm. 
The earstones represented by fig. 20 have the upper and lower margins 
nearly parallel, one end is obliquely truncated, but the other is pointed ; 
in the smaller specimens both ends are rounded, and they are all pro- 
portionally smaller than those of the plaice or the long rough dab. 
Pleuronectes flesus, Linn. The Flounder or Fluke. PI. i. B, fig. 18. 
The earstones represented by fig. 18 were obtained from a fish of 
average size, but its exact length was not recorded, and they are the only 
examples included among the photographs of the present series. They 
have an outline somewhat resembling the earstones of the plaice, and 
measure about 65mm. in length by fully 4°5mm. at the widest part. 
