III.— SOME NOTES ON FISH PARASITES. 



By Thomas Scott, LL.D., F.L.S. 



(Plates III.-V1I.) 



Papers containing records and descriptions of parasites more or "less 

 peculiar to fishes have been contributed at various times to Part III. of the 

 Annual Reports published during previous years by the Fishery Board 

 for Scotland. In the present paper there are notes on several additional 

 species, some of which are interesting because of their strange and unusual 

 forms. 



These notes have been prepared from specimens obtained at various 

 times chiefly in connection with research work undertaken on behalf of 

 the Board, but a few have reached me from other sources. Some of the 

 specimens have been in my possession for several years, while others have 

 only recently been obtained. 



I am indebted to my colleague, Dr. Williamson, for some of the species 

 recorded, and to my son, Andrew Scott, A.L.S., for the drawings and 

 photographs with which the paper is illustrated. 



The species to be described comprise examples both of the Ectoparasites 

 and the Endoparasites of fishes. Three species belonging to the former 

 group appear to be new to science, while some rare and curious forms are 

 included among those belonging to the second group. 



The various species mentioned in the sequel are arranged and described 

 in the following order : — 



(1) Ectozoa. 

 CRUSTACEA. 



COPEPODA. 



Pandarus hiro/ur, Leach, var. 

 Hatschekia eorriigerti, .sp. n. 

 Chondr acanthus WUMaWisom, sp. n. 



PLATYHELMINTHA. 



Trematoda-ectoparasihga. 

 Octobuthrium Sybillce, sp. n. 



(2) Entozoa. 

 Trematoda Endoparasitica. 



Distoma cestoides, Ed. van Beneden. 



Cestoda. 



Bothriocephalus proboscideus, Rudolphi. 



„ punctatus (Rudolphi). 



Ancistrocephalus microcephalics (Rudolphi). 



