618 NOTES AND MEMORANDA. 



measured across anus, are correspondingly 63 per cent., 65 per cent., 

 and 50 per cent, of the total length. The head, measured along the 

 side from the spines on the snout to the posterior margin of the 

 opercular flap, is 35 per cent, in the first two specimens, in the third 

 29 per cent, of the total length ; the ordinary values for this dimen- 

 sion are 25 to 27 per cent. The pectorals are 41 to 44 per cent, 

 of the total length, except in the third specimen, where they are 

 normal — namely, 30 per cent. The ventrals are also of great length. 



These dimensions help to display the appearance of the specimens. 

 The head seems large and elongated, almost sunk into the thick and 

 deep anterior region of the body. In proportion to the head, the body 

 ought to be 30 cm. long, whereas it is only 20 to 22 cm. Similarly 

 the pectorals, which, except in the third specimen, extend to the root 

 of the tail, are obviously out of proportion, likewise the ventrals. 

 These alterations in the proportions are due not to any structural 

 deformity, but to the shortness of the vertebrae ; these seem com- 

 pressed together and broad in proportion to their length, and the 

 other parts of the body are compelled to follow suit. The internal 

 organs were well developed, and more especially the air bladder, which 

 was apparently larger than normal. Two of the specimens were males, 

 apparently mature ; the third was an immature female. 



Halibut (Hippoglossus vulgaris, Flem.), or Pole-Dab {P/euronectes 

 cynoglossus, Linn.). 



Two young pleuronectid post-larviie were taken in the bottom-net in 

 the Moray Firth in August, 1896, and though there is some doubt as 

 to their identity, it seems advisable to publish a short notice of them. 

 It is so seldom that one naturalist is able to obtain a complete series 

 of the young forms of any fish with pelagic eggs and larva^, that 

 it requires the co-operation of several to differentiate one form from 

 another. Early stages of both these forms have already been described 

 by other observers, and a description of the present specimens — of a 

 stage undescribed as yet — may aid to their more exact determination 

 and to a fuller knowledge of the young stages of one or other of 

 the species. 



The spawning season of the halibut, ascertained from the observa- 

 tion of ripe specimens, seems to be chiefiy towards the end of April 

 and beginning of May, so far as Britain is concerned. Unripe 

 specimens, however, have been obtained in June, and at Iceland from 

 June to August seems to be the spawning time.* The pole-dab, again, 

 appears to have a similar spawning period. Cunninghamf obtained 

 the ripe eggs on the west coast of Scotland towards the end of June, 



* British Marine Food-Fishes, Mcintosh and Masteinian. 

 t Trans. Jioij. Soc. Edinbur(jh, vol. xxxii., jiart i., p. 101. 



