ably Part I1I.— Twenty-third Annual Report 
same species of Zabrus in the month of March. Several specimens were 
found on the gills of the Zabrus from the Moray Firth and from the 
North Sea, but none were very perfect. This species of Microcotyle is 
not only very slender, but is also without consistence, and therefore 
easily injured. The length of the specimen represented by the drawing 
is 53mm. Figure 22 is a front view of one of the suckers seen under 
a moderately high magnification. 
Microcotyle labracis, van Beneden and Hesse. Pl. vi., fig. 21. 
1863.  Microcotyle labracis, v. Ben. and Hesse, Recherches, 
p. 112, pl. xi1, figs. 12-18 
This species has a general resemblance to J/. donavani, but differs in 
possessing about double the number of suckers at the posterior end 
(fig. 21). The structure of the cesophagian bulb also differs in the two 
species. 
The length of the specimen represented by the drawing is about 7mm, 
Habitat.—On the gills of the Bass, Labrax lupus. I am indebted to 
my son for specimens of this species, 
Fam, GYRODACTYLIDA. 
Genus Diplectanum, Diesing (1858). 
Diplectanum equans, Diesing. PI. vi., fig. 24. 
1858. Diplectanum equans, Diesing, Revis. der Myzhelm., p. 77. 
1863. Diplectanum cequans, v. Ben. and Hesse, Recon 
p. 122, pl. xili., figs. 9-22. 
This Trematode is common on the gills of the Bass, Labrax lupus, but 
being very small it is easily missed. The length of the specimen repre- 
sented by the drawing (fig. 24) is about 2mm. 
In Diplectanam cequans the head is armed with two moderately strong 
hooked spines on each side of a deeply concave cleft ; this cleft is occupied 
by a process thickly covered with minute prickles, as shown in the 
drawing. 
I am indebted to my son for this small but interesting species. 
The folluwing is a list of species belonging to the Trematoda that have 
been described or recorded, and for the most part figured, in Part III. of 
the Annual Reports of the Fishery Board for Scotland. The species now — 
recorded are included in the list. The names are arranged in alphabetical 
order. 
Annual Report where published, 
Name of the Species. and Number of Plate where 
figured. 
Acanthocotyle monticellii, T. Scott, - | 20th Report; Pl. xiii.; 1902. 
Anthocotyle merluccii, v. Ben. and Hesse, | 19th __,, Pl. viii. ; 1901. 
Callocotyle kréyert, Diesing, - =) haley 5 Fe a 
Dactycotyle pollachii, v. Ben. and Hesse, | _,, - is 
Diplectanum aequans, Diesing, — - - | Present Report ; Pl, vi. 
Epidella hippoglossi, O. F. Miller,  - | 19th Report; no figure. 
Heterocotyle pastinace, T. Scott, - -dyegnd’ ig. Pl. xvii.; 1904. 
