St. Andrews Marine Laboratory. 95 



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

 microscope tlic parts mentioned h.ive a yellowish hue. 



Next clay (29th Aj)ril) the embryo was distinctly yellowish 

 under a lens, the most cons|)ieu(<U3 chromatophorcs bein^^over 

 the yolk and the oil-<2;lobule. Ku|)ffer'3 vesicle had disap- 

 peared, and the tail extended beyond the yolk, which liad con- 

 siderably diniinisiicd, as it' proi^Mens 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 274 millim. The 

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

 yellow chromatophorcs, 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 papillie 

 being much smaller, while they were not conspicuous on the 

 body. Moreover, no ramifying dark chromatopliores existed at 

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

 oil-globule was situated about the posterior third of the yolk-sac, 

 a position corresponding with that in the topknot. The 

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

 existed in tiie eyes. When viewed from the ventral surface 

 the pectoral thickenings were distinct, and the heart formed a 

 pa))illose 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 j)Osteriorly, and granules lay in the centre a short 

 distance witiiin 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 tlie fin was very small. 

 The notochord was multieolumnar. 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 resembling that o/" Arnoglossus megastoma 



Donov. 



An Q^Q was met with in considerable abundance in the 

 tow-nets opposite the curing-station at Gairloeh, Koss-shire 

 on the 21st March, 1S94. It had a diameter of 1*2573 

 • Kesenrcbes, ibid. pi. xvii. fij^. 4. 



