[Reprinted from Twenty-third Annucd Report of the Fishery Board for 

 Scotland for the Year 1904— Part III— Published August 1£, 1905.] 



HT.—OBSERVATIONS ON SOME PARASITES OF FISHES 

 NEW OR RARE IN SCOTTISH WATERS. 



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

 sent to him many years ago from the Moray Firth by the late Thomas 

 Edward of Banff. 



My son, Andrew Scott, A.L.S., has prepared the drawings which 

 illustrate this paper. 



PART I.— COPEPODA PARASITA. 



Family Ergasilid^i. 

 Genus Bomolochus, Nordmann (1832). 



Bomolochus solece, 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 Gyclopterus lumpus that the first specimens were observed, early in 

 1 900, 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 

 gadidae. The following are the names of the fishes :— Cydopterus 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 flesus L., 

 the Flounder. Bomolochus soleoz was first found on the back of the 

 common Sole— Solea vulgaris, Quen. 



