268 
Proceedings of Boyal Society of Edinburgh. [sess. 
Additional Observations on the Development and Life- 
Histories of the Marine Food-Fishes, and the Dis- 
tribution of their Ova. By Prof. W. C. MTntosh. 
Abstract. 
(Read July 20, 1891.) 
Since the previous communication to the Society by the author 
and Professor Prince, not a few dubious points have been cleared 
up, and, by the courtesy of the Fishery Board for Scotland, further 
investigations on the general subject carried out at the St Andrews 
Marine Laboratory. Under the former head may be mentioned the 
large unknown pelagic egg, with a spacious pri vitelline space, termed 
Ovum of Pleuronectid B. This has been proved by Mr E. W. L. 
Holt to be the egg of the Long Bough Dab, so that the ambiguity 
which has existed since the Trawling Expeditions of 1884 is now at 
an end. The larval and early post-larval stages of the species have 
already been described and figured. A more detailed series of 
observations have also been made on the development of the Lemon 
Dab or Lemon “Sole,” as it is somewhat ambiguously termed, 
showing how readily ova can be transmitted long distances, and 
the larval and post-larval stages reared subsequently. Formerly, 
only the ovarian egg of Muller’s Topknot was described and 
figured ; now the fertilized and free-floating egg and its develop- 
ment have been studied. Like the egg of the Turbot and Brill, this 
has an oil-globule. The larva is tinted of a deep gamboge-yellow on 
head, trunk, and upper part of yolk-sac, while the oil-globule is con- 
spicuous at the posterior and lower part of the yolk by an environ- 
ment of the same bright hue. 
Amongst forms hitherto unknown is an ovum somewhat less than 
that of the Gurnard, with a large privitelline space and an oil- 
globule. Its development has only been partially followed, and its 
relationships are unknown. The ova of the three-bearded rockling 
have been procured in great numbers along with other two species 
of the same group, and the changes during development described. 
The most interesting additions, however, are those connected with 
the larger and the lesser Sand-eels, the reproduction of which was 
