1889. ] ENTOZOA IN THE BRITISH MUSEUM. 323 
At present I give only a figure of this new species to ensure its 
recognition. The detailed description, with anatomical remarks, 
will be given in a forthcoming paper. ‘The lengths of the cysts 
of this new species are 6-10 millim. 
Didymozoon serrani is the first species of this genus found ina 
fish of the family Percidee, the other known species inhabiting fishes 
of the families Scombride and Sphyrzenidee. 
CESTODA. 
7. GyRocoryLeE RuGosa, Diesing, Syst. Helm. vol. i. p. 480. 
A specimen taken from the intestine of a Callorhynchus antare- 
ticus from Dunedin (New Zealand). This very strange Cestode has 
hitherto been found only in Mactra edulis. 
8. BoTaRiocePHALus MACROBOTHRIUM, sp.n. (Plate XXXIII. 
figs. 7, 8, 9.) 
Head small, with the terminal cupula flattened ; bothria lateral, 
small, prominent, with thick margin ; neck very short, subcylindrical ; 
body flattened. Anterior segments very small, hardly to be dis- 
tinguished, becoming gradually more distinct towards the end of the 
body. The last segments not different in form from the preceding, 
but a little larger. Genital orifices lateral and in the anterior part of 
the segments. 
Length of the specimens 16-20 centim. 
The specimens were taken from the stomach of a Trachypterus, 
sp- inc., from Mauritius, presented by L. Bouton, Esq. 
9. BoTHRIOCEPHALUS PLATYCEPHALUS, sp.n. (Plate XX XIII. 
fig. 10.) 
Head pointed, triangular, pyramidal, anteriorly truncated, without 
distinct terminal cupula. Bothria large, much flattened, with in- 
distinct fossette; neck very short, quadrangular; body flattened. 
Anterior segments small, the succeeding gradually larger ; posterior 
margin arcuate ; genital orifices lateral. Lengths of specimens 115— 
190 millim. 
The host of this new species is Beryx decadactyla of Madeira, 
from which Entozoa have not been previously described. 
10. BoruriocerHaALus TETRAPTERUS, von Siebold, in Lehrbuch 
d. vergl. Anat. d. wirb. Thiere, Berlin, 1848, pp. 120, 148, 147, in 
notes. (Plate XXXIII. fig. 11.) 
I complete Siebold’s description of this species, which inhabits 
Phoca vitulina :—Head cordiform. Bothria lateral, enlarged, with 
margins expanded, so as to resemble four wings. Anterior segments 
trapezoidal, distinctly campanulate; the following rectangular, not 
campanulate, the later decidedly quadrate. I have not observed 
the incomplete transverse division of the segments described by 
Siebold. The male and female generative organs are double in 
each segment, with two distinct genital orifices, very small, situated 
