540 d. j. scourfield, synopsis of the known species of 



Parasitic Copepoda. 



Caligus 0. F. Muller. 



C. rapax M. Edwards [Baird (1)]. 



Recorded by Baird (1) from Lough Neagh, where it w^as taken 

 on trout and pollan {Coregonus jjollan), 



C. curtus 0. F. Miiller [Baii-d (1) = (7. miilleri]. 



Also from the pollan in Lough Neagh. 



It is very doubtful whether the two foregoing species ought to 

 be included in a list of fresh-water Copepoda, in spite of Baird's 

 records from L. ISTeagh. They seem to be distinctly marine forms. 



Lepeophtheirus v. Nordmann. 



L. stromii Baird [Baird (1)]. 



Found on salmon and salmon-trout. 



Lernaeopoda Blainville. 



L. salmonea (Gisler) [Baird (1)]. 

 Taken on the gills of the salmon. 



Lernaeocera Blainville. 



L. cyprinacea (L.) [Baird (1)]. 

 Occurs on carp, bream, and roach. 



Achtheres v. Nordmann. 



A. percarum v. Nordmann. 



I have seen specimens from a trout caught in Loch Bannoch. 



Thersites Pagenstecher. 



T, gasterostei Pagenstecher [Scott (48)]. 



Recorded by T. Scott (22) from Barra, R. Forth, and Aberdeen. 

 It occurs on the inside of the gill-covers of the three-spined 

 Stickleback {Gasterosteus aculeatiis). 



The following table, showing the distribution of the free- 

 swimming forms of British fresh-water Copepoda, has been 

 prepared in similar form to that adopted in Part I. for the 

 Cladocera. The column devoted to "Midland England" has 

 been omitted, however, as it was impossible to obtain sufficient 

 records for this district. 



