248 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



also containing numerous longitudinal fibers. The belly in this sex at maturity is 

 prominent (a feature specially noted by Mr. Holt), as in the cod, pollack, and others. 



On March 31 Mr. R. Duthie, assistant fishery officer at Lerwick, Shetland, skill- 

 fully fertilized a series of ova at 4 p. m. and transmitted them to St. Andrews. At 6 

 p. m. on April 3 all seemed to have perished, but a more careful survey of the demersals 

 showed that there were some living eggs on the bottom. These had a diameter of 

 1*0287 mm., whereas others from the same fish, imperfectly preserved in weak picric and 

 spirit, had a diameter of 1-1430 mm. The general appearance of the egg resembled that 

 in the cod, and the micropyle agreed with that of the haddock. The blastopore was 

 still open, and the optic vesicles had formed. The perivitelline space varied in size. 



On April 4 the blastopore had closed (with radiate streaks) and Kupffers' vesicle 

 had formed. The muscle plates were defined and the notochord more evident. The 

 yolk presented a faintly granular aspect, perhaps from indications of the future pig- 

 ment corpuscles. The pectoral folds are large and show many granules. The radiate 

 strands of the latter region had become only distinct on April 6, and black chromato- 

 phores had appeared over the yolk, while indications of similar pigment were present 

 along the body. The black chroinatophores had generally increased on April 7, though 

 there were variations in this respect. On the 8th the sides and yolk-sac of the embryo 

 had a series of conspicuous black chroinatophores, and the tip of the tail now reached 

 the head. The arrangement of pigment thus prominently differs from that in the cod 

 and foreshadows the more general distribution of the chroinatophores so characteristic 

 of the species in the young condition. One hatched on April 9, the color being similar 

 to that described in the advanced embryo. All the eggs remained throughout on the 

 bottom of the vessel, but retained vitality. 



It is remarkable that so few opportunities of seeing the fertilized ova of this 

 species have occurred, and yet it is a common form on the eastern and western coasts. 



REMARKS ON THE EGGS AND YOUNG OF THE HALIBUT. 



The ripe females of this species seem to have been met with chiefly toward the 

 end of April and beginning of May. Those observed last year* were procured on the 

 former date, those of this year on the latter, viz, on the 5th of May. It was thought 

 last year, from the condition of the specimens, that the zona radiata of the eggs in 

 this species was delicate; such, however, is not the case. 



In size they are among the largest pelagic eggs known, ranging from 3-0861 

 to 3-8 mm. Raffaele, in the Bay of Naples, appears to have found none over 3 mm. in 

 diameter, though Wenkebach subsequently procured one of 4 mm. The capsule (zona 

 radiata) shows faint scribbled markings, as first mentioned by Mr. Holt, who obtained 

 the eggs at Grimsby about the beginning of May last year. In those from Bergen 

 Bank the markings resembled fine creases or folds, which sometimes even assume a 

 stellate arrangement like those of the lemon dab or brill. The usual minute punc- 

 tures occur all over the surface. The folded edge of the zona radiata is marked by 

 closely arranged stria?, an appearance often seen in the shriveled eggs of other species. 

 A simple micropylar orifice only occurred, without surrounding lines, and it generally 

 presented a pinkish hue, probably from refraction, as in the large pores in the egg of 

 the torsk. This form has been included under the pelagic eggs, both from its appear- 



*Tenth Animal Report of the Fishery Board for Scotland, part in, p. 285. 





