454 Holt — On the Eggs and Lnrvce of Teleosteans. 



observations from some ova of this species which he is at present developing. I 

 cannot find these markings in ruptured zonae, from which the larva has escaped, 

 and they are very faint in dead and decomposing ova. 



Only a single egg (fig. 19) of this species, with a diameter of 1-25 mm,, and 

 showing the peculiar marking of the zona, occurred in the tow-nets, viz. in the 

 surface-net, in Tnver Bay, on June 25th. 



It is at a stage somewhat in advance of that shown by Cunningham in his 

 figure 7 {op. cit.), having a free caudal region about equal to the rest of the body, 

 and a broad marginal fin. Pigment is altogether absent, though black chromato- 

 phores are shown by Cunningham in the figure alluded to, having first appeared 

 on the previous day. 



Professor M'Intosh pointed out to me long ago that a temperature slightly 

 higher than normal frequently brings about a ^^recocity of pigment, a phenomenon 

 very noticeable in the development of the sprat. This probably accounts for the 

 difference in the condition of pigmentation in Cunningham's ova and my own, 

 though the latter, a single specimen, may perhaps be abnormal. Three days later 

 I found that the larva had escaped, and was darting actively about the vessel, 

 occasionally resting for a time at the surface. 



It is now (fig. 39) apparently at a stage between those shown by Mr. Cunning- 

 ham in figures 8 and 9, and does not altogether agree with his descriptions. The 

 length is 3 '98 mm., a little longer than Mr. Cunningham's newly escaped larva. 

 The snout projects boldly, but the mouth is as yet unformed, though'the branchial 

 bars are visible. The mid-brain {m. h.) is rather prominent dorsally, its greatest 

 height being behind, instead of in front of, the middle of the eye, as in Cun- 

 ningham's figure 9. The nasal sacs (o/.) are apparent just in front of the eyes, 

 which to some extent overlap them. The otocysts, which are omitted in 

 Cunningham's figure 8, are large, of the usual shape, but somewhat upwardly 

 rotated on the hinder ends, and lie a little distance behind the eye. The pectorals 

 {p.f.) are considerably developed, they have undergone a partial rotation, and are 

 somewhat in advance of the position at which these organs usually make their first 

 appearance. 



The gut is large and tubular. It displays two dilatations close behind the 

 pectoral fins, representing the liver and stomach. The intestinal region of the gut 

 is very ample, and there is a sharp constriction immediately in front of the rectal 

 region (r,), which ends blindly short of the margin of the ventral fin, appearing in 

 this respect to be somewhat abnormal. The anus is as yet imperforate, and there 

 is no appearance of an urocyst. The yolk (?/.) is narrow and elongated, and the 

 space in front of it, spoken of by Cunningham as the venous sinus, is much smaller 

 than in either of his figures. The posterior end of the heart (/*.) is against the 

 front wall of the yolk. The marginal fins are rather narrow, the dorsal com- 



