Notes from the St. Andrews Marine Laboratory. J89 



XXVII. — Notes from the St. Andrews Marine Laboratory 

 {under the Fishery Board for Scotland). — No. XIV. By 

 Prof. M'Intosh, M.D., LL.D., F.R.S., &c. 



1. On the Ova and Young of Hijjpoglosstts vulgaris. 



2. On the Ova and Larvse of Gadus nwiutus. 



3. Ou the Ova and Larva) of Brosmius brosme. 



4. On the Ova and Larvaa of Arnoglossus megastoma. 



5. On a Hermaphrodite Example of Mytilus modiolus. 



1. On the Ova and Young (?/" Hippoglossus vulgaris. 



The ripe eggs of the halibut have hitherto escaped observa- 

 tion. The spavs^ning-period, indeed, even in the case of 

 Fishery Officers stationed where hundreds are landed monthly, 

 is full of uncertainty, so much so that Dr. Fulton, in working 

 up the returns in regard to reproduction, could come to no 

 definite conclusion as to the spawning-period of this species. 



Parnell was of opinion that the halibut spawned in spring. 

 J. Couch, again, does not allude to the subject, though 

 R. Couch, according to Day, gives April as the spawning- 

 period. I3uckland quotes the statement of Parnell, and adds 

 that the roe is of a pale red colour and the ova numerous, a 

 remark, however, that is applicable to many forms. Day 

 adds nothing to the foregoing. Mobius and Heincke observe 

 that the spawning-period occurs in spring, and state that 

 Malm found on the Cattegat a ripe female on the 26th of 

 April. Fulton, again, procured an advanced specimen, 

 captured east of the Island of May, with the ovaries of a 

 pinkish tinge, on the 18th of February, and others less 

 advanced in June. The eggs in the former case were com- 

 paratively large, while in June they measured 1*27 millim. 

 in diameter, but they were far from being ripe, as indeed 

 were various specimens Dr. Fulton kindly forwarded to 

 St. Andrews in May and June^ 1891. No ripe example was 

 seen amidst many hundreds from Iceland and Faroe on the 

 pontoon at Grimsby about the middle of the latter month. 

 About the beginning of May, 1892, Mr. Holt, who is carrying 

 out important fishery work at Grimsby, kindly informed me 

 that he had secured the fresh eggs of this species, and that 

 they ranged from 3'07 to 3*81 millim. in diameter, were 

 destitute of an oil-globule, and delicate to handle. The cap- 

 sule had faint scribbled markings. The eggs collapsed and 

 burst very readily, and he thought it possible that a large 

 perivitelline space was formed after fertilization, as in tlie 

 long rough dab. They are thus the largest pelagic eggs in 

 our seas ; indeed, Eaffaele appears to have found none at 



Ann. & Mag. N. Hist. Ser. 6. Vol. xiv. 14 



