NOTES ON TELEOSTEAN OVA AND LARVAE. 51 



chromatophores occurring about the neck region and shortly afterwards 

 on the eyes. Yellow chromatophores (bright lemon-yellow by reflected 

 light, brownish by transmitted light) next appear on the sides of the 

 embryo above tlie dense line of black pigment above-mentioned (see 

 Fig. 5). At about the same time black chromatophores frequently 

 appear along the dorsal surface of the yolk-sac adjacent to the trunk of 

 the embryo. The circulatory fluid is now of a red colour, which is 

 plainly visible at the heart systole. Before the appearance of the 

 yellow pigment the blood was colourless, but even then its circulation 

 could be observed in vessels from the yolk-sac, and in the aorta and 

 main arteries of the head. A day or two after the appearance of 

 yellow, an increase takes place in the amount of black pigment, a 

 double ventro-lateral line being formed on each side with the inferior 

 pair, which are the more distinctly marked, coming together at the 

 anus. A sprinkling of lateral chromatophores next appears, and the 

 eyes become so dark as to be conspicuous to the naked eye. The only 

 other black pigment in the anterior region is a pair of lines converging 

 towards the occiput from the posterior lateral part of the yolk-sac. 

 The yolk-sac and occipital region are covered with diffuse pale yellow. 



The newly hatched larva (see Fig. 16) has a length of 4'26 mm., of 

 which about five-eigliths is pre-anal. The remnant of yolk is relatively 

 small, as is usual with larvae from demersal eggs, and bulges out on 

 each side of the larva. A small oval swim-bladder is present. Rounded, 

 stellate, black chromatophores uniformly beset the sides of the trunk 

 in fairly regular lines, which are about four deep transversely in the 

 pre-anal and about three deep in the post-anal region. These are 

 larger in the anterior part of the body than posteriorly. There are 

 similar lines of yellow chromatophores (pale lemon coloured by re- 

 flected, brownish by transmitted light) slightly less numerous and at 

 greater interval. These are more densely distributed posteriorly than 

 anteriorly. The most dorsal row of chromatophores are yellow and 

 these are of a larger si/e and greater denseness than the others. Over 

 the straigl.t intestine uilow pigment is generally sparse and sometimes 

 quite lacking. The ^^.jsterior portion of the tail, for about 1 mm., is 

 quite unpigmented, as is also the median strip along the whole dorsum. 

 Tlie only pigment in the larval fins consists of a small group of about 

 three to five black chrouiatophores in the anal fin immediately behind 

 the anus. The snout is rounded. The large otocysts are situated 

 immediately behind the eyes. The dorsal fin arises a little behind the 

 level of the posterior edge of the yolk-sac. Tiny epidermal vesicles 

 densely cover the embryonic fins, except along the margin of its most 

 posterior part, 



