THE TREMATODE PARASITES OF FISHES. 



467 



Judging by those figures this is probably the largest and most repre- 

 sentative investigation which has hitherto been made on this subject. A 

 comparison with the numbers dealt with in my previous reports will 

 perhaps be of interest. For St. Andrews, Millport., and Aberdeen the 

 corresponding figures are as follows : — 



St. Andrews.- Millport. 

 Species. Fislies. Species. Fishes. 



Aberdeen. Total. 



Species. Fishes. Species. Fishes 



From this it is evident that the material examined at Plymouth was 

 richer, not only in the gross total examined, but also in the variety of 

 specimens, than the corresponding material from the other three localities 

 combined. Of the individual groups only the Anacanthini and Physos- 

 tomi were not so well represented at Plymouth as in these other localities. 



In these four series of investigations I have thus examined a total of 

 845 fish belonging to 102 different species, giving an average of a little 

 over 8 fish of every species. Some specimens have naturally received 

 more attention than others, and those most exhaustively dealt with 

 have been the sprat {Clupea sjyrattus), the common dab {Pleuronecfes li- 

 manda), Lepadogaster gouanii, Ammodytes tobianus, the mackerel {Scom- 

 ber scombrus), and the butter fish {Centronotus gunnellus). Other fishes 

 which have received a large measure of attention have been the horse- 

 mackerel, the sea bream, the whiting, and the John Dory. 



From these four localities the aggregate figures are : — 



Acanthopterygii 

 Pharyngognathi 

 Anacanthini . 

 Physostomi . 

 Lophobranchii* 

 Elasmobranchii 



Total 



The Sun-lish (Mola mola) is included here. 



