88 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
INTERNAL PARASITES AND DISEASED 
CONDITIONS OF FISHES. 
By JAS. JOHNSTONE. 
(WITH FIVE PLATES.) 
CoNTENTS. 
) PARACOTYLE CANICULAE, Gen. et Sprc. Nov. 
) KOELIIKERIA FILICOLLE. 
3) PONTOBDELLA LAEVIS. 
) VARIOUS PATHOLOGICAL CONDITIONS —Fipromata 
AND SaRcoMaé IN EDIBLE FISHES. 
(1) PaRACOTYLE CANICULAE, GEN. ET SP. NOV. (PL. I.) 
This Trematode inhabits the head of the Common 
Dogfish, principally in the region of the gill slits. It was 
first found by Mr. A. Scott, when trawling from the 8.8. 
‘* John Fell,’’ in the Irish Sea, south from the Calf of 
Man, in June, 1905; and a preliminary description was 
given in 1906.* It was regarded then as a species of 
Epibdella, but there were some notable differences from 
the characters diagnostic of that genus, and as only two 
or three specimens were obtained Mr. Scott left the animal 
unnamed. During the last two years, however, the species 
has occurred in large numbers on the dogfishes living in 
the Aquarium tanks at the Port Hrin Biological Station, 
and this abundance of material has enabled me to give 
an adequate description. I am indebted to my colleague, 
Dr. W. J. Dakin, for fixing and preserving specimens for 
detailed histological examination. The species appears 
to be new to science, and I describe it here as Paracotyle 
caniculae, with the following diagnosis :—One anterior 
sucker, terminal or sub-terminal, leading into a vestibule, 
or prepharynx, into which opens the pharynx. Posterior 
*A Scott, ‘“ Faunistic Notes.” Ann. Rept. Lancashire Sea-Fish, 
Laby. for 1905; p. 48, Pl. VII, Fie. 1. Liverpool, 1906. 
ae 
