EGGS AND LAHV^ OF TELEOSTEANS. 113 



The ova were apparently adhesive, similar to those of the herring, but 

 considerably smaller (Report on the Sprat Fishing of 1883-84, Second Annual 

 Report of the Scottish Fishery Board, 1884). 



The eggs of Alosa sapidissima have received much attention from the 

 United States Fish Commission, They differ from those of the herring in not 

 being adhesive ; they are deposited in fresh or brackish water, and are but 

 slightly heavier than the water itself, so that they remain in a state of 

 suspension near the bottom. It is a curious fact that, although the artificial 

 cultivation of shad ova has been practised on such a large scale in America, no 

 memoir on the development of the fish has appeared in the publications of the 

 U. S. Commission. I have not been able to find any figure of the ova at any 

 stage of development, but Mr John A. Ryder, in a paper on the absorption of 

 the yolk in embryo fishes [Bulletin U. S. Fish Commission, vol. ii., 1882), gives 

 a figure of the anterior region of a larval Alosa, some days after hatching. All 

 that can be drawn from this figure is that the notochord is multicolumnar. 



Fam. 23. Bathythrissid^e. 



„ 24. CHIROCENTRIDiE. 



„ 25. Alepocephalidve. 



s , 26. NOTOPTERID^E. 



„ 27. Halosaurid^e. 



Fam. 28. Hoplopleurid^e. 

 „ 29. Gymnotid^e. 

 „ 30. Symbranchid^e. 

 31. Muraenid^e. 



A great deal has been written about the reproductive organs of Anguilla 

 and Conger. The fertilised ova have never been seen, but young eels about 2^ 

 inches long are common enough in canals and rivers in spring. Specimens 

 from the Forth and Clyde Canal were brought to me in April 1886. For an 

 account of the investigations which have been made into the reproduction of 

 the eel, see G. Brown Goode, Bull. U. S. Fish. Commission, vol. i., 1881. 



From the above survey it is seen that no physostomous fish is known at 

 present to have pelagic ova. In the newly-hatched larvae, at present known, 

 the anus is separated by a considerable interval from the yolk sac. In the 

 Clupeidse the notochord is unicolumnar, but this is not a feature common to the 

 order, as that organ is multicolumnar in the newly-hatched Salmo. It seems 

 pretty certain that the problematic ovum, which Agassiz and Whitman 

 identified as belonging to Osmerus mordax, is derived from some physostomous 

 fish. V. Hensen suggested, in a letter to me, that it was the ovum of the sprat, 

 but without evidence this is improbable, and it is not supported by the account 

 of the sprat's ovum given by Duncan Matthews. As no one has seen the 

 embryo of the eel, it possibly belongs to Anguilla, but in that case one would 

 expect to find the ova more plentiful. 



VOL. XXXIII. PART i. p 



