FISH-CULTURAL INVESTIGATIONS AT ST. ANDREWS, SCOTLAND. 249 



ance and structure, but since it has never been obtained in a tow net in the neigh- 

 boring seas it is possible it may be less buoyant than the smaller eggs. 



The larval and post-larval stages of the halibut have hitherto escaped notice. A 

 form procured by the Git Hand, on Smith Bauk, in June, 1880, off' the coast of Caithness, 

 however, approaches what is conceived to be the type of this genus. It is distinguished 

 by the great thickness of the body (the depth of which, moreover, is comparatively 

 moderate), by the character of the head, and the presence of branchiae projecting 

 behind the opercula. It is not a very young fish, to judge from the thickness and firm 

 ness of the body and the condition of the branchiae, yet the embryonic tail (opisthure) 

 is still present. The total length is 9-5 mm., and the greatest depth is about 3-8 mm. 

 The vent is situated a little in advance of the median line of the body, which is 

 speckled with minute brownish-black points (in spirit) on the head and lateral regions, 

 and by similar specks over the abdomen, the latter chromatophores, however, having 

 uudergone considerable change from the spreading out of the marginal pigment, while 

 a black speck remains in the center. The chromatophores on the lateral region are 

 somewhat regularly arranged. Indications of two pigment-touches occur in the dor- 

 sal (marginal) fin, viz, one above the tip of the pectoral, and the other about the center 

 of the first abdominal region of the body. Ventrally a single patch is situated midway 

 between the anus and the hypural region. The pigment invades the fin, and thus 

 resembles that in the pleuronectids generally. On viewing the dorsum from above, the 

 cephalic and the two marginal touches, which extend to the tin, are best seen. Ven- 

 trally a little pigment over the abdomen and the patch in the anal fin are noticeable, 

 while chromatophores are dotted round the anus. The pigment is alike on both sides. 



The eyes are of considerable size and are lateral in position. The marginal fin is 

 injured, but seems to have been of moderate depth, traces of true rays appearing both 

 dorsally and ventrally, and particularly in the caudal. The terminal curve of the 

 notochord is pronounced, but does not taper much, and the embryonic fin forms a 

 shorter lobe than in the pleuronectids hitherto examined. A few black specks occur 

 inside the abdominal cavity. 



The thickness and elongation of the body of this specimen suggest its relationship 

 to the halibut, yet nothing in its structure would militate against its being another 

 form. I am inclined, however, to connect it with the species mentioned. 



Specimens of the young halibut are extremely rare, perhaps because they are 

 found only in deep water on the great fishing-grounds. The smallest examples hitherto 

 examined here were two from St. Andrews Bay, the larger being a foot long. They were 

 obtained by a local trawler, but similar specimens are occasionally caught on lines. 

 Last year a specimen, apparently of this species, was procured in the deeps about 50 

 miles from Norway on May 31, measuring 07 mm., or a little over 3f inches. It had 

 been swallowed by a green cod. The tin formula is D. 07, A. 73 ( "?), caudal 10, pectoral 

 11, pelvic 6, though it must be stated that digestion had considerably affected the fins. 



The chief differences between this and an example 1 foot long are the proportion- 

 ally larger size of the eyes and their proximity to the anterior border of the snout — 

 the smallness of the gape — the posterior angle of the mouth being somewhat in front 

 of the eye; whereas in the larger (1 foot) it passes to the anterior fifth of the eye, and 

 the maxilla is boldly marked. The arch of the lateral line behind the eye on the right 

 side is much more pronounced in the larger specimen, for in the smaller it is gently 

 curved upward and runs forward with a very slight declivity. On the left side the 



