Holt — On the Eggs and Larvce of Teleosteans. 465 



free caudal region, and exhibits no striation of the yolk-sac, which may probably 

 be attributed in the other to ill-health. 



Five small black chromatophores occur over the oil-globule, and the yolk-sac 

 is very sparingly decorated in a similar manner. Small stellate black chromato- 

 phores occur on the top of the brain, and in a row along each side of the dorsum, 

 except in the free caudal region, where there is a single median dorsal row. 

 There is a prominence {I. s. o. ?) on either side of the anterior region of the body, 

 which perhaps represents a lateral sense organ. 



These ova were lost on the 17th June, by the upsetting of my aquaria in a 

 heavy roll, and I never obtained any other specimens. 



This form is rather smaller than the egg of 3IoteUa mustela, with a rather 

 larger oil-globule, the colouration of which is distinctive. The pigmentation of 

 the embryo is also more precocious than in 31. mustela, and is differently arranged 

 (c/. Brook, " The Development of Motella mustela^'' he. cit). It agrees with the 

 egg of M. tricirrata in the arrangement of the pigment, and in the presence of 

 colouration in oil globule, but differs in size, the egg of this species, according to 

 Raffaele [op. cit., p. 37), having a diameter of '75 mm., with an oil-globule of 

 •218 mm. 



It seems probable that the present form is a Gadoid, possibly Motella cimhria. 



Species IV. — Ctenolabrtis rupestris. (?) 

 PI. XLViii., figs. 23 and 24. PI. xlix., figs. 28-30. 



These pelagic ova occurred in the surface-net, in Blacksod Bay on the 15th 

 June, and in Inver Bay on the 20th and 25th June. They were not abundant. 



The egg is sphei'ical, with a diameter of "835 mm., and the zona is thin and 

 minutely pitted, the yolk translucent and homogeneous. There is no oil-globule. 

 The perivitelline space is small. The younger stages exhibit no distinctive 

 characters. Black pigment appears at the time when the free caudal region 

 becomes noticeable (fig. 23), and is arranged in a row of small chromatophores 

 along each side of the body, except in the caudal region. A few very minute pig- 

 ment dots occur at intervals between the outer rows, and there are several 

 larger chromatophores on the top of the brain. 



A specimen obtained on the 20th June exhibited the first formation of the 

 embryonic shield. Two days later the embryo was far advanced (fig. 24) having 

 a free caudal region equal to the rest of its length. The body is very slender. 

 The crystalline lens is fully formed ; the heart beats actively. The otocysts (ot.) 

 are visible as small ovoidal sacs, with otoliths, remote from the eye. The lateral 

 row of black chromatophores extends some way along the free caudal region. 



