246 



Part III. — Eleventh Annual Report 



9. — On an Unknown Larval Fish having only Black Pigment. 



Amongst the larvae which had hatched in the collection . of eggs for- 

 warded from the fishing-ground 160 miles off Aberdeen (E. by N.) was 

 a form having a peculiarly elongated caudal region, and finely ramose 

 black pigment on the head, body, and tail (PI. XII. fig. 5). The marginal 

 tin appears to be somewhat narrow. 



This form was not discriminated till it had emerged, so that the egg 

 presented no peculiarity. Mr Holt states that the larva of the pollack 

 has only black pigment, but very little seems to be known of this species. 



10. — On the Spawning Period of the Pollack. 



Last year Mr R. Duthie, Assistant Fishery Officer, procured ripe eggs 

 of this species on the 7th May,* and this year the same active officer 

 found ripe eggs in a fish caught 20 miles east of Lerwick, Shetland, on the 

 5th May. The ova were received at the laboratory on the 8 th, partly in 

 sea-water and partly in solution. The diameter of those in the water was 

 1*2954 mm., but they were not in a satisfactory condition. In the solu- 

 tion (made by a local chemist) they ranged from 1-0668 to 1*1430 mm. 



11. — Further Remarks on Young Pleuronectids, including the 

 Turbot, Brill, and Topknot. 



The capture in a tow-net during the night of the 23rd June 1893, by 

 the laboratory attendant (A. W. Brown) of a young Rhombus (turbot- 

 like), 10 mm. in length, and at a stage differing from anything hitherto 

 available, affords a further opportunity for again referring to the younger 

 stages of the sinistral forms mentioned above, and of clearing up certain 

 obscurities in which they are at present involved. 



The specimen (PI. XII. fig. 6) measures fully 10 mm. in total length, 

 but its breadth cannot be accurately giveu, since the tips of the fin-rays 

 are considerably injured, and the ventral edge lacerated from the hyoidean 

 region to the middle of the anal fin. In life it much resembled a young 

 flounder in colour, and was difficult to detect ; indeed, the attendant lost 

 it in the jar, and only recovered it after death had made the tissues more 

 opaque. When it reached the laboratory, it was more or less in tbe latter 

 condition, with a slightly yellowish hue of the body, which, with the 

 head, was dotted all over with large and small black chromatopkores. 

 The dorsal fin had six black touches, and portions of two were present 

 in the anal, which, as already mentioned, had been injured. Tke most 

 distinct of these touches began at the finely-dotted line of black pigment 

 at the inner border of the interspinous bones, and proceeded distally into 

 the tin-rays almost to the tip. The pigment on the head was irregular] y 

 scattered, and the same may be said of that on the body, though, in tlie 

 case of the latter, the larger chromatopkores are observed to be densest in 

 two longitudinal streaks, in tke upper kalf of the region. Tke eyes are 

 large and silvery, while the great size of the head, the structure of the 

 mouth, and the hyoidean region are diagnostic. The head, indeed, is so 

 large that it is only about a fifth less than half the diameter of the entire 

 animal to the posterior border of the hypurals. Minute spines occur along 

 the opercular border and a portion of the surface inferiorly, above the 

 eyes and elsewhere over the snout. Such spines are characteristic of 

 the somewhat later stages of the turbot (PI. XII. fig. 7) at the length 

 of 14 mm., in which the opistkure is still very evident at tke upper 

 border of the caudal, and also in a slightly older specimen figured 

 in the ' Marine Invertebrates and Fishes of St Andrews ' (PI. VI. iigs. 

 5 and 6), but whether they are also present in the young brill Of similar 

 stages is still an open question. It is probable that they are present. 

 * Tenth Annual Report of Fisher 7/ Board for Scotland, Part III. \>. 28b. 



