THE TREMATODE PARASITES OF FISHES. 485 



terus punctatus and Newphis aequoreus. The species is now known to 

 occur in thirty species of British marine fishes, and it is, w^ith the 

 exception of Derogenes varicus, the most widely distributed of all British 

 fish parasites. In the above list the bream {Sjxirus centrodontus) from 

 which the parasites were obtained were bought in the London market, so 

 that their actual origin is unknown. None of the bream examined at 

 Plymouth harboured the parasite. 



Although so widely distributed, the parasite shows a distinct preference 

 for Gadoid fishes, of which eleven species have been found to harbour it. 

 I have myself examined over 120 Gadoids and found the parasite in 

 34% of them. Amongst the total number of other fishes which. I have 

 examined it has been present in less than 5%. Next to the Gadoids, 

 Cottus bubalis and Hippoglossus vulgaris are probably the most frequent 

 hosts. 



Heminrus ocreatus (End.). 



=H. LUHEI Odhner. 



Odhner, 1905, p. 352 ; Nicoll, 1909, pp. 21-2. 



By far the commonest host of this parasite was found to be the pilchard 



{Clupea pilcliardus). It was also met with on one occasion in each of the 



following hosts : Trachurus trachurus, Capros aper, Scomber scombrus, 



Gadus merlangus, and G. pollachius. 



Sub-Family (Dinurinae). 



Genus LECITHOCLADIUM Liihe. 



Lecithocladium excisum (End.). 



Looss, 1907, pp. 131-2. 



This species was found only in the stomach of the mackerel {Scomber 



scombrus). It occurred in three out of eight specimens examined. 



Sub-Family Sterrhurinae. 



Genus LECITHOCHIEIUM Liihe. 



Lecithochirium rufoviride (End.). 



Looss, 1907, p. 147. 



This was found in the stomach of the common eel {Anguilla vulgaris), 



the conger {Conger conger) and the angler {Lophius piscatorius). It is an 



extremely common parasite of the first two fishes, but has not previously 



been recorded from Lophius. Looss regards the conger as the only 



authentic host of the parasite, but there is no doubt that the single 



