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Part III. — Tenth Annual Report 
features which link them on to the older forms. Mr Holt's descriptions 
and figures will soon be published, but it may be noted that, besides the 
form of the head and the otocystic spines, the abdomen has a median and 
two lateral pigment-bands which seem to be characteristic, though traces 
of such occur in other young pleuronectids. In Mr Holt's words — 
1 Besides the pigment of the median ventral line of the 4 abdomen, a 
4 line of black, with a few yellow, chromatophores occurs on either 
4 side of it. They diverge from a point in rear of the rectum, run 
4 forward along the ventro-lateral region, and reuniting in front of the 
' pelvics, form a complete loop. This condition at first suggested a 
1 division of the ventral embryonic fin-fold, such as is described by 
' M'Intosh and Prince in their unknown larval pleuronectid (?) A, but 
' close examination of both of the entire specimens and of transverse 
* sections failed to show the presence of any elevation of the surface. Six 
1 very distinct pigment-patches occur on the dorsal, four (including the 
1 hypural patch) upon the post-anal segment of the ventral fin, though the 
* pigment of the trunk is not correspondingly broken up into bars, but 
1 forms continuous lines on the dorsal and ventral edges. As appears to 
4 be usual in post-larval pleuronectids, the black pigment is more abundant 
4 on the ventral than on the dorsal fin. The base of the pectoral fin is 
4 profusely pigmented, and numerous small chromatophores are scattered 
' over the sides of the head and jaws and on the snout.' He further notes 
that in certain of his specimens sufficient progress had been made to show 
that it was a sinistral form. Of course it cannot yet be absolutely proved 
that these are the young stages of the brill, but the previous remarks on 
the turbot and the older stages of the brill would make such a reasonable 
surmise. 
Mr Holt's oldest examples were 9 mm. in length and approached that 
figured by Raffaele, though his had more profuse pigment. The fin-ray 
formula is — Dorsal, 80 Ca • Ventral, 66 Ca. There is a discrepancy, he 
points out, between this and the adult, but probably considerable change 
occurs during development. He further adds — ' With the increase in 
' the height of the body there is a more than corresponding increase of 
4 length in the interspinous region, which, as we know from RafFaele's 
* observations, is responsible for the advance of the dorsal fin in front of 
1 the head. But the same cause is meanwhile operating in the opposite 
4 direction, with the result that some of the posterior fin-rays get thrust 
4 upon the blind side of the caudal peduncle. This occurs, as I know from 
4 observation, in R. megastoma, II. platessoides, A . laterna, and P. cynoglossus, 
4 and I think there is no reason to doubt it takes place in the turbot and 
4 brill. We find the presence of rays on the blind side of the caudal 
4 peduncle as an adult character in the topknots, where it is 
4 obviously to be interpreted as the retention of a larval character ; but we 
' find no such condition in the adults of the other species enumerated.' 
Mr Holt obtained no specimens intermediate between the stage men- 
tioned and one of about 70 mm. (dorsal 81, ventral 63). Raffaele 
describes and figures two earlier stages, viz., of about 16 mm., and 
another of 25 mm., with dorsal 80, ventral 60. The otic spine?, 
according to Mr Holt, are as well marked as in specimens of 10 mm. In 
a post-larval Solea, Raffaele mentions a blunt epidermal process on each 
side in connection with the otocyst (Tav. 3, fig. 6). 
The discovery of the elongated young form with otocystic spines by 
Mr Holt off the west coast of Ireland, and which, as already indicated, 
he connects with the brill, has caused a re-examination of all the speci- 
mens available, and especially of such stages as that represented in 
PL XIX. fig. 1 of the Researches, and this examination has been con- 
siderably facilitated by the kindness of Mr Holt, who forwarded the 
above-mentioned young stages of the brill-like form, and also similar 
