NOTES ON TELEOSTEAN OVA AND LARVAE. 53^ 



embryonic fin arises in the occipital region, the caudal part of it being 

 spatulate. The head is rounded and the mouth terminal, the otocysts 

 situated immediately behind the eyes. Pigmentation is extremely 

 rich. Black chromatophores are the most abundant, covering the sides 

 of the trunk and gut in closely set and fairly regular longitudinal 

 lines. The largest chromatophores are those on the dorsal surface of 

 the head, and those along the dorsal contour are the largest and most 

 closely set of those on the trunk. Post-anally the number of chro- 

 matophores counted transversely is four or five. About 0'8 mm. from 

 the posterior end of the notochord, the greater part of the pigmenta- 

 tion ceases, but there may be a few small pigment spots over the 

 notochord behind this point. Along the anal fin there is a line of 

 black chromatophores, extending from immediately behind the anus to 

 the hypural area. Mid-laterally, where the black pigment is least 

 dense, there is an irregular line of about seven large lemon-yellow 

 chromatophores, extending from the level of the posterior edge of the 

 yolk-sac to a little behind the anus. Between all the other chromato- 

 phores are numerous small orange-coloured ones, with a relatively 

 large, clear, central space, which gives them the appearance of small 

 rings. Most of the black and yellow chromatophores also have the 

 form of radiations from a central unpigmented spot. Small, round or 

 stellate chromatophores of a pure red colour occur on the ventral 

 surface of the abdomen anterior to the anus. There is no yellow or 

 orange pigment over the sides of the abdomen, but only black, and it 

 is perhaps worthy of note to mention that the black chromatophores 

 of this region appear to have a different structure from those over the 

 rest of the body, the centre of the spot in this case being pigmented 

 instead of clear. The proximal part of the median fin membrane 

 shows the same minute vesicular structure as was seen in L. bima- 

 culatus, but the vesiculation does not extend so near to the margin. 



A slightly older larva measured 57 mm., and was 3-2 mm. from snout 

 to anus. At four or five days old the length is 6-3 mm., the pre-anal 

 portion being 3*4 mm. A hypural thickening is visible. The pigmenta- 

 tion at this age is practically the same as in the newly hatched form, 

 except for an increase of red pigment on the inferior parts of the body. 

 A larva in which the yolk has been entirely absorbed shows small red 

 chromatophores on the ventral surface of the lower jaw, on the ventro- 

 lateral part of the opercular region, on the ventral and ventro-lateral 

 surface of the abdomen and over the basal part of the large pectoral 

 fins. 



The pelagic post-larval stages of X. r/ouani can be easily distinguished 

 from those of L. himacidatus by their larger size at the same point in 



