THK TREMATODE PARASITES OF FISHES. 487 



Gadus merlangus, and Zeugopterus norvegicus. Though fairly widespread, 

 it is by no means a common parasite, and its numbers in any particular 

 host rarely exceed two or three. 



Sub-Family Syncoeliinae. 

 Genus DEROGENES Liihe. 

 Derogenes various (0. F. Mtiller). 

 Odhner, 19U5, pp. 360-4 ; Johnstone, 1907, pp. 188-92 ; 

 Lebour, 1908, pp. 45-6. 

 By far the commonest of marine fish parasites, this species was found 

 in the stomach of twenty-eight different hosts, namely, Mullus harbatus, 

 Sparus centrodontus, Trachurus trachurus, Capros ajjer, Zeus faher, 

 Trachinus vipera, T. draco, LopJiius piscaiorius, Coitus bubalis, Agonus 

 cataphractus, CalUonymus lyra, Trigla pini, T. gurnardus, T. hirundo, 

 Cyclopterus lumpus, Blennius ocellaris, Gadus luscus, G. minutus, G. 

 77ierlangus, G. pollachius, Molva molva, Onos tricirmtus, Bothus maximus, 

 Pleuronectes flesus, P. limanda, Solea vulgaris, Salmo trutta, and Conger 

 conger. 



Genus HEMIPERA Nicoll. 

 Hemipera ovocaudata Nicoll. 

 Nicoll, 1913a, pp. 242-3. 

 This species was found a few times in the stomach of Lepadogaster 

 gouanii. 



Genus DEROGENOIDES Nicoll. 

 Derogenoides ovacutus Nicoll. 

 Nicoll, 1913a, pp. 243-6. 

 This parasite was met with only once in the stomach of a weever, 

 Trachinus draco. 



Family BUNODERIDAE. 



Genus BUNODERA Railliet. 



Bunodera nodulosa (Zeder). 



Looss, 1894, pp. 33-41. 



A few specimens of this species were obtained from the intestine of a 



trout {Salmo trutta) from the River Yealm. 



