>S'^ Andreios Marine Laboratory. 95 



tint is visible under a lens, but under a low power of the 

 microscope the parts mentioned have a yellowish hue. 



Next day (29th April) the embryo was distinctly yellowisli 

 under a lens, tlie most conspicuous chromatophores being- over 

 the yolk and the oil-globule. KupfFer's vesicle had disap- 

 peared, and the tail extended beyond the yolk, wliich had con- 

 siderably diminished, as if progress were rapid. The otocysts 

 were indicated by two ovoid translucent structures, and the 

 heart was faintly outlined. The larval fish emerged before 

 8 A.M. on the 1st May, and measured 2-74 millim. The 

 head, body, and yolk-sac were dotted all over with canary- 

 yellow chromatophores, and at 11 a.m. a few had a tendency 

 to throw out processes. The yolk-sac was more finely reticu- 

 lated than in the topknot *, the minute vesicles or papillee 

 being much smaller, while they were not conspicuous on the 

 body. Moreover, no ramifying dark chromatophores existed at 

 the border of the marginal fin, dorsally and ventrally. The 

 oil-globule was situated about the posterior thirdof the yolk-sac, 

 a position corresponding with that in the topknot. The 

 olfactory sacs, lenses, and otoliths were present, but no pigment 

 existed in the^ eyes. When viewed from the ventral surface 

 the pectoral thickenings were distinct, and the heart formed a 

 papillose tube inclined to the left. Traces of segmental ducts 

 occurred at the sides of the notochord, with enlargements in 

 the pectoral region. _ The alimentary canal terminated some- 

 what bluntly posteriorly, and granules lay in the centre a short 

 distance within the tip. A band from the urinary vesicle 

 and the end of the gut passed to the fin-border a short distance 

 behind the yolk, the distinction in this respect between the 

 present species and the topknot, as figured by Prof. Prince, 

 being marked. The preanal portion of the fin was very small. 

 The notochord was multicolumnar. The larva was very 

 buoyant, keeping quite to the surface of the water, so that 

 currents wafted it readily about in a vessel ; and, moreover, 

 it soon wriggled forward at short intervals. 



The development of this form is comparatively rapid, and, 

 so far as can be observed, it most nearly approaches the 

 turbot. 



3. On an Egg resemhUng that o/" Arnoglossus megastoma 

 Dotiov. 



An egg was met with in considerable abundance in the 

 tow-nets opposite the curing-station at Gairloch, Ross-shire 

 on the 21st March, 1894. It had a diameter of 1-2573 

 * Eesearches, ibid. pi. xvii. tig. 4. 



