THE FLOUNDER FAMILY. 339 



The capsule presents externally under the microscope an 

 irregular basket-pattern, similar to that of the lemon-dab, 

 and a slight sheen. In many, moreover, a series of minute 

 globules formed a zone round the larger oil-globule. The 

 blastoderm had not quite enveloped the yolk and the majority 

 of the eggs were unhealthy or dead. Even temporary examination 

 in several instances sufficed to prove fatal, a rare occurrence 

 with healthy eggs. The embryo was outlined, and the optic 

 vesicles distinct. On the 7th, closure of the blastopore took 

 place, and next day Kupffer's vesicle appeared (Plate IV, fig. 3). 

 On the 12th a considerable portion of the tail was free (Plate 

 III, fig. 2.5). On the 13th May (13th day after fertilization), one 

 or two emerged from the capsule, and floated languidly at the 

 surface. A few escaped at intervals until the 15th May. On 

 the whole, however, not more than twelve or fifteen were hatched 

 out of the whole series, and the vitality of these was low, since 

 none survived more than two or three days. The development 

 of the brownish and black pigment on the trunk of the em- 

 bryo was characteristic, approaching very closely the arrange- 

 ment in the turbot, though the tints were by no means the 

 same, since what was yellow in this species was reddish by 

 transmitted light in the turbot. Yellowish and black chroma- 

 tophores were present in connection with the oil-globule, and 

 the yolk had numerous yellowish pigment-specks. The black 

 chromatophores on the head and body were stellate or ramose, 

 and minute black grains occurred in the eye. The skin was finely 

 vesicular. It will thus be seen that the hybrid brill is much 

 more boldly flecked with black, and that there is a tendency to 

 yellowish as well as brownish in its coloration. 



Immediately after extrusion the young hybrid (Plate XIII, 

 fig. 7) was about 2'6 mm., as measured by Prof. Prince. 

 The yolk-sac was large and round, with the oil- globule placed 

 at the posterior border, and somewhat above the ventral edge. 

 Its position thus corresponds nearly with that in the turbot. 

 The head, body and marginal fin present a normal appearance, 

 and differ from the sketch of the brill given by Dr Raffaele^. 

 The dorsum of the head has black and brown pigment-corpuscles, 

 1 Op. cit. tav. i, fig. 18. 



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