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Part III. — Tenth Annual Report 
and which I had the privilege of perusing, Mr E. W. L. Holt has 
pointed out that the unknown egg (F), with the oil-globule and its larval 
and post-larval stages, described in the Researches, though approaching 
the egg and young of the turbot, yet presented certain differences. This 
conclusion, as already stated, had been held at St Andrews, at first 
mainly by the fact that the pelagic egg of every other common pleuro- 
nectid had been determined, that an egg occurring not unfrequently 
throughout the season must belong to a form well known in the 
neighbourhood, and subsequently by the appearance of the egg in the 
ripe turbot. It is true the ripe ova of a turbot of 12 lbs. were seen 
during the trawling expeditions of 1884 (10th July), but in the midst 
of many duties in the open sea, all that could be done then was to see that 
they were pelagic, and consign them to spirit, especially as no male could 
be procured for fertilisation.* It was observed that the eggs were small, 
only a little larger than those of the rockling, and the embryos, many of 
which were hatched from pelagic ova of the same appearance, captured 
by the tow-net on the spot, were likewise small. 
Mr Holt found that at St Andrews the eggs termed F, in July 
and August had a diameter of -82, and that of the oil-globule, *1 1 mm. 
A single egg obtained in Valencia harbour on the 27th March measured 
•75 mm., the diameter of the oil-globule being "15 mm. Moreover, he 
hatched this egg, and found that the larva agreed with species F, figured 
in the Researches. He points out, however, that in his larval fish the 
anus did not at first reach the edge of the marginal fin, but this condition 
was not noticed by Professor Prince or myself, though it may readily 
have been overlooked. Mr Holt gives the length of the larva as 2*51 mm. 
'From the snout to the imperforate anus is 1" mm., and an interval of 
1 '11 mm. separates the latter from the hinder margin of the yolk. The 
' notochord is multicolumnar.' When two days old ' the total length is 
' 3 '57 mm., of which the preanal region occupies 1'37 mm. An interval 
' of '21 mm. separates the anus (now marginal) from a perpendicular from 
1 the hind margin of the yolk. A great increase has taken place in 
* the breadth and extent of the marginal fin,' so that the larva now has 
the characteristic appearance of a pleuronectid. ( The separation of the 
* rectum and yolk appears to indicate a relationship to a sinistral rather 
' than a dextral form (cf. Agassiz and Whitman, Rhomboidichthys, and 
.* Raffaele, Rhombus levis). 7 On the other hand, he finds that the ripe 
unfertilized ova of the turbot vary from -99 to 1*06 mm., and the oil- 
globule from "20 to "21 mm. 
In the Researches, at p. 846, a post-larval form, not uncommon in deep 
water, is described, and the suggestion that this sinistral pleuronectid 
may be the turbot was thrown out. As, however, no continuous series 
from these up to the undoubted young turbot has been obtained, consider- 
able dubiety remains, indeed, from the progress made by the right eye, it 
would seem to pertain to a smallerfish than the turbot, possibly the topknot, 
an opinion shared by Mr Holt. It is a remarkable fact, indeed, that up to 
this period the life-history of so important a fish as the turbot should present 
so many blanks. The same forms were obtained in considerable numbers 
by Mr Holt during his recent work off the west coast of Ireland, and he 
has been enabled to give reliable drawings from life, and thus record 
more accurately their form and coloration. Little, however, can be added 
to the description of these early forms up to 9 mm. Mr Holt likewise 
could make out no spines on the otocystic region, such being present in 
the young of another young form apparently connected with the brill. In 
PI. XIV. fig. 7, the early jDOst-larval stage of this sinistral pleuronectid is 
figured, unfortunately, from a somewhat softened spirit-preparation and 
* By treating these eggs with spirit, acetic acid and camphor, the oil-globule is 
easily observed. 
