8 
Larval Trernatodes 
Ringed Sand Plover (Aegialites hiaticula), Black-Headed Gull (Larus 
ridibundus), Herring Gull {Larus argentatus), Oyster Catcher {Haema- 
lopus ostralegus), and Redshank {Totanus calidris). Of these the only 
one which has the ventral sucker greater than the oral is Maritrema 
hiimile from the Redshank but in other ways this does not agree with 
our species. 
Jagerskiold (1908) gives a summary of the characters of Maritrema 
and divides up the species of the genus into groups, also describing 
some new species. Of these his Maritrema suhdolum from the Common 
Sandpiper {Actitis hypoleucos) comes very near the present species, 
although I do not think they are identical. 
At Millport I have examined many birds for the adult worms but 
as yet without success. 
A larval Opisthorchis encysted in the skin of Gadoids. 
In September 1912 Dr Jas. Johnstone kindly sent me pieces of 
a Haddock {Gadus aeglefinns) the skin of which was spotted at frequent 
intervals with black, each spot marking the presence of an encysted 
larval Trematode. Owing perhaps to the preservative it was difficult 
to make out the structure of these worms, the cyst being extremely 
tough and difficult to break through. Enough was seen however to 
show that it was a Distornid. Gamble and Drew (1912) noticed the 
same appearance in a Whiting {Gadus merlangas) but in this the 
parasite was identified by them as probably a species of Holostomum. 
It is evident that many Trernatodes cause the segregation of pigment 
granules in the neighbourhood of the cysts. Nicoll (1907 c) found an 
encysted Trematode in a Gottus bubalis also with black pigment. 
Williamson (1911 a and b) notices the same thing in the “Spotted 
Haddock ” but believes his specimens to be Gasterostomum gracilescens, 
i.e. the same species that inhabits the nerves of that fish. There are 
also several examples from American fish, notably the Trout (Linton 
1911, p. 252). 
It was not until this summer (1913) that I managed to study 
a Trematode in the skin of a Lythe from Millport which evidently 
belongs to the same species as those in the Haddock sent to me by 
Dr Johnstone. Lythe {Gadus pollachnis) and Saithe {Gadus virens) ave 
frequently spotted in this way at Millport and they come quite close 
to the shore so long as the water is fairly deep. In Jan. IJII, 
Mr Elmhirst sent me portions of the skin of a Cod with similar 
spots which contain the same worm. 
