III.—SOME NOTES ON FISH PARASITES. 
By Tuomas Scorr, LL.D., F.LS. 
(Plates I1T.—V1iT_) 
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 io 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 
iacluded 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 bicolor, Leach, var. 
Hatschekia cornigera, sj. n. 
Chondracanthus Williamsont, sp. 1. 
PLATYHELMINTHA. 
TREMATODA-ECTOPARASITICA. 
Octobothrium Sybille, sp. un. 
(2) Entozoa. 
TREMATODA ENDOPARASITICA. 
Istoma cestowles, Ed. van Beneden. 
CESTODA. 
Bothriocephalus probosctdeus, Rudolphi. 
punctatus (Rudolphi). 
Ancistrocephalus microcephalus (Rudolphi). 
