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71 Part III.— Twenty-fourth Annual Report 
Genus Zeugopterus. 
Zeuyopterus punctatus (Bloch). Miiller’s Topknot. Pl, i. B., figs. 42 
and 43. 
The earstones represented by the figures 42 and 43 are from two 
fishes, one of them being 84 inches and the other 54 inches in length. 
These earstones are small and somewhat oval in shape, but deeply notched 
and truncate in front. One side, the inner one, is slightly convex and 
is longitudinally grooved, but the reverse side is smooth. Those of the 
larger fish are nearly 4mm. long by 2°5mm. in greatest width; those of 
the other fish are 3mm. in length, and rather wider than the larger one. 
Genus Lepidorhombus. 
Lepidorhombus Whiff (Walb.). Sail Fluke, Whiff, or Megrim. Pl.i.B., 
figs. 31 and 32; pl. ii. B., figs. 1-5; pl. v., figs. 1 and 2. 
The earstones of a megrim about 17 inches long are represented by 
fig. 1, pl. ii. B., and fig. 2, pl. v., and they measure about 7mm. in length 
by nearly 5mm. in greatest width. The length of these earstones is thus 
about the one-sixtieth part of the entire length of the fish. 
In the megrim, as has been already stated, the earstone on the left side 
differs somewhat in shape from the one on the right side, and this 
difference is observable even in the earstones of the smaller fishes, but 
perhaps not in very young specimens ; I find that in such specimens the 
characteristics peculiar to the species or genus are usually obscure or 
undeveloped. This will be more readily perceived by comparing the 
photographs of the earstones of the larger megrim mentioned above with 
those of the two smaller fishes represented by figs. 31 and 32, pl. i. B., 
and which measure respectively 168mm. and 87mm. in length. Compare 
also with the earstones represented by fig. 5, pl. ii. B., which are those of 
a fish 11 inches in length. 
In the examination of large fishes or of those of moderate size the 
difference in the shape of the earstones is readily noticed, one of them 
being pear-shaped—that is, broadly truncated and somewhat emarginate 
at the posterior end, with the lateral margins boldly rounded and 
converging towards the narrow anterior extremity; the lower edge is 
- tolerably even, but the other is scarcely so regular. The curve of the two 
sides is slightly different, and this makes the anterior extremity appear 
as if it were turned somewhat upward. Each earstone is also slightly 
incurved on the outer aspects, the inner being correspondingly convex. 
The other earstone, like the last, is also widest posteriorly, but the 
posterior end is obliquely truncated and deeply, and sometimes irregularly, 
notched. The entire lower edge is boldly curved and tolerably even, 
but the upper margin, though it has the posterior portion nearly straight 
or slightly rounded, and more or less distinctly crenulated, is towards the 
front end interrupted by a considerable break in its continuity ; this 
break appears to be more distinct in the earstones of larger fishes, and 
the presence of this break causes the anterior extremity to terminate in a 
tolerably sharp point. 
I have already given the size of the earstones of the largest fish 
examined, and the sizes of a few of the others will be found in the 
annexed Table. 
A ame * 
Aeneas Cities Stetina lt EP 
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