62 
Genus — Plectanocotyle (Diesing). 
Plectanocotyle caudata, n. sp. (Plate V., figs. 4 — 7.) 
This worm is very common on the gills of the Grey Gurnard, 
occurring in about 50 per cent., and often in numbers. Its 
anatomy is so like Plectanocotyle lorenzi, Monticelli,* that, I think, 
I cannot be wrong in placing it in this genus; indeed, if it were 
not for the long posterior peduncle in the centre of the hind part 
of the body and its armature being slightly different, it might be 
the same species. Also, the six chitinous suckers surrounding 
the posterior margin in my specimens are on distinct though short 
peduncles or cupules, whilst those in Monticelli's figures are sessile ; 
this, indeed, may be contraction due to the preservative. In many 
ways both Plectanocotyle lorenzi and the present species are like 
Van Beneden's and Hesse's Phyllocotyle yurnardi,\ but here again 
the chitinous posterior suckers are sessile. I might hazard the 
suggestion, however, that Phyllocotyle gurnardi, Plectanocotyle 
lorenzi, and my specimens all represent the same species in various 
degrees of contraction. As it is impossible to prove this at present, 
I must describe my worm as a new species, as I cannot make 
it agree exactly with either of the other two forms. T. Scott J 
records both Phyllocotyle gurnardi and Plectanocotyle lorenzi from 
the Grey Gurnard, but they are so much alike that, according to 
Scott, one could easily be mistaken for the other, except for the 
peduncle. Scott's figure of Phyllocotyle gurnardi is apparently the 
species I am at present describing. Monticelli himself identified 
the Plectanacotyle lorenzi found by Scott. A. Scott § records Phyllo- 
cotyle gurnardi from the Common Gurnard and Yellow Gurnard from 
the Irish Sea, but does not describe it. 
The Trematode which I have called Plectanocotyle caudata is a 
very fragile species, from 4 to 6-5 mm. in length without the 
peduncle, which is about 07 mm. long. The greatest breadth is 
0-80 mm. in the region of the ovary. The body gradually tapers 
at each end, and at the posterior end widens again and spreads 
out in a shield-shaped fan, about 1 mm. long and about the same 
width. At the hind end of the fan is a long slender peduncle 
bearing a round sucker, 0-20 mm. across, which is armed with 
small chitinous hooks. The fan itself is scolloped out, and bears 
* Monticelli, F. S., "Di una nuova specie del genera Plectanocotyle." Atti della R. Acca- 
demia del Scienze di Torino, vol. XXXIV., 1899, page 1015. 
"I" Van Beneden and Hesse, op. cit., page 103. 
% Scott, T., " Twenty-third Annual Report of Fishery Board for Scotland, " pages 115-116. 
§ Scott, A., " Some Parasites found on Fishes in the Irish Sea." Op. cit., page 30. 
