46 FaH III. — Twenty-eighth Annual Report 



VI.— NOTES ON THE EGGS OF THE ANGLER {LOPHIUS PISCA- 

 TORIUS), HALIBUT {HIPPOGLOSSUS VULGARIS), CONGER 

 VULGARIS, AND TUSK {BROSMIUS BROSME) ; A YOUNG 

 ARNOGLOSSUS, sp.; ABNORMALITIES IN LOPHIUS, 

 GADUS, RAIA; DISEASES IN GADUS, PLEURONECTES, 

 ONOS, ZOARCES; OCCURRENCE OF HIMANTOLOPHUS 

 RHELNUARDTI, AND CLUPEA PILCHARDUS ; THE 

 EFFECTIVENESS OF A SEINE-TRAWL IN A SMALL 

 POND. By H. Chas. Williamson, M.A., D.Sc, F.R.S.E., Marine 

 Laboratory, Aberdeen. 



(Plates IL-VI.) 



CONTENTS. 



PAGE. 



The Eggs and Lai'vae of the Angler (i^op/im-s^isca?o»'fK.s), - - - 46 



The Ripe Eggs of the Halibut (Hippoglossus vulgaris), - - - - 48 



The Eggs of the Conger [Conger vulgaris), - - - - - 48 



The Eggs of the Tusk (Brosmius brosme), - - - - - 50 



A Post larval Arnoglossus, ....... 51 



A Rare Angler {Himantolophus rheinhardti), - - - - - 51 



An Angler-iish with One Eye, ....... 53 



Hermaphroditism in the Cod (Oadus caUarias), - - - - - 54 



A Peculiar Cod from Loch Eyne, ------- 55 



Stone in the Bladder of a Cod, .-..-.. 56 



Cod Bitten by a Cephalopod Mollusc (?), ..... 56 



Injured Cod, .---..... 57 



Tumours from the Cod, ---.-... 57 



Tumours on a Lemon Sole [Pleuronectes mkrocephalus), - - • - 59 



Disease on the Skin of Onos miistela, - - - - - - 59 



Tumours in a Zoarces viviparus, -.-..-. 59 



Spotted Whiting (Gadus merlangus), Cod, and Lythe (Gadus pollacJmis), - 59 



Nematodes in the Muscle of a Cod, - - - - - 61 



Sandeels [Ammodytes, sp.) and an Hermit Crab [Eupagurus bernhardus) 

 encysted in the Abdominal Cavity of the Haddock (Gadus ceglefinus), 



Cod, and Saithe (Gadus virens), - - - - - - 62 



Abnormal Roe of an Haddock , - - - - - - - 64 



Abnormal Skate (Raia circnlaris and clavata), - - - - - 64 



On the Effectiveness of a Seine-trawl in a small pond, - - • - 65 



Explanation of Letters used and Plates, ------ 65 



The LarvcB of the Angler {Lophius piscatorius). 



The larvae of the American Lophius piscatorius have been described by 

 Agassiz,* and those of the British example by Prince.f 



An opportunity occurred in July, 1907, of studying the larvae of this fish, 

 A large mass of the spawn was sent in a herring-barrel to the Laboratory by 

 Mr. Caird, Sandhaven. It arrived on the 15th July. Many of the eggs 

 were alive when the mass was transferred to a tank of sea-water. 



The embryos, which were black, were already moving about inside the 

 eggs. The oil globule was also pigmented black. The general appearance of 

 the embryo did not seem to indicate that it was in a very advanced stage 

 of development ; the tail of the embryo was very short. As was pointed out 

 by Prince, the short tail only partially encircles the yolk when the embryo 

 is ready to emerge. 



'' Proc.Amer. Acad. Sci., 1882. 



t " Notes on the Development of Angler Fish (Lophius piscatorius)," 9th 

 Annual Report of the Fishery Board for Scotland, for 1890, Pt. III., p. 343, 1891, 



