318 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



The other characters of the cestode need no descrip- 

 tion, as a glance at an everted proboscis is sufficient to 

 distinguish the species. 



Tetrarhynchus tetrabothrius, van Beneden. 



Hosts : Raia clavata and Acanthias vulgaris. 



This cestode can generally be distinguished by the 

 presence of the four ear-shaped bothria and by the shape 

 and arrangement of the hooks. On one side of the 

 proboscis seven hooks can generally be seen. They are 

 about 0*017 mm. in length, have expanded bases and 

 sharply recurved apices. 



II.— TREMATODA. 



Distomum appendiculatum, Rudolphi. 



Hosts : Pleuronectes platessa, PL limanda, New 

 Brighton shore. 



In the summer of 1904 Mr. Gr. Eccles procured for 

 me a large number of small flukes Jin. to lin. long from 

 the sandpools on the New Brighton shore. These were 

 dissected by the fishermen attending the classes at Piel, in 

 order to see the characteristic method of feeding on 

 copepoda adopted by small pleuronectid fishes of this size. 

 In quite a number of these tiny fishes a small appendicu- 

 late Distome was found which is D. apjiendiculatum. This 

 trematode is probably far more widely distributed than 

 any other endo-parasitic member of the group. 



P. Olsson (loc. cit.) gives the following list of fishes in 

 which the species is found : 



Cottus scorpio, Clupea harengus, 



Salmo salar, C. spratta, 



S. fario, Gadus morrhua, 



Corregonus oxyrhynchus, Gr. minutus, 



