108 Part III —Twenty-third Annual Report 
IIlL—OBSERVATIONS ON SOME PARASITES OF FISHES 
NEW OR RARE IN SCOTTISH WATERS. 
By Tuomas Scort, LL.D., F.LS., &c. 
Plates V. and VI. 
In Part III. of the Twenty-second Annual Report of the Fishery Board 
for Scotland, I published a small paper on some parasites of fishes new to 
the Scottish marine fauna. Since the issue of that paper several other 
rare and interesting species have been examined, and these I now propose 
to describe. 
The species to be described belong for the most part to the Copepoda ; 
but there are also five species belonging to the Trematoda. As these 
parasitic Copepoda and Trematoda are quite distinct groups, my observa- 
tions on them are, as in the previous paper, divided into two parts, viz., 
Part I. Copepoda parasita, and Part II. Trematoda. 
I have been indebted for several of the species described here to Dr. 
H. ©. Williamson; Mr. Bowman and Mr. Irvine have also obtained a 
few interesting species for me. Canon A. M. Norman has also allowed 
me the privilege to examine one or two rare Copepoda in his collection, 
Edward of Banff. 
My son, Andrew Scott, A.L.S., has prepared the drawings which 
illustrate this paper. 
PART I.—COPEPODA PARASITA. 
FaMILy ERGASILIDS. 
Genus Bomolochus, Nordmann (1832). 
Bomolochus solew, Claus. 
This species of Bomolochus has quite recently been obtained in the 
nostrils of Gadus luscus, which adds another to the number of fishes now 
known to harbour these Copepods in their nostrils. It was in the nostrils 
of Cyclopterus lumpus that the first specimens were observed, early in 
1900, but soon afterwards they were obtained in the nostrils of some other 
fishes, and notably in those of the cod Gadus morhua, where they appear 
to be of quite frequent occurrence. The fishes in whose nostrils the 
copepods have been most commonly obtained are those belonging to the 
gadide. The following are the names of the fishes :— Cyclopterus lumpus 
L., the Lumpsucker. Gadus morrhua L., the Cod-fish. Gadus ceglefinus 
L., the Haddock. Gadus merlangus L., the Whiting. Gadus luscus L., 
the Brassie. Gadus pollachius L., the Lythe. Molua molva L., the 
Ling. Pleuronectes platessa L., the Plaice, and Pleuronectes jflesus L., 
the Flounder. Bomolochus solee was first found on the back of the 
common Sole—Solea vulgaris, Quen. 
sent to him many years ago from the Moray Firth by the late Thomas " 
v 
