69 Part [I1I.—Twenty-erghth Annual Report 
Octobothiium leptogaster, Leuckart. Pl. VIL, figs. 2-5. 
1842. Octobothriwm leptogaster, Leuckart, Zool. Bruchst., vol. iii. 
p. 29, Bl. i.) figs Ds Pl LL, fie? 2, 
In this species the posterior end is considerably expanded, and the eight 
suckers, which are moderately large, are situated at the ends of short 
finger-like processes which are spread out in the form of a fan. The body 
is extremely slender, especially the posterior portion extending from the 
fan-like expansion with its eight suckers, forward to the anterior thickened 
genital portion. This slender portion, which seems to have suggested the — 
specific name, is much longer and more flexible than the anterior thickened 
part ; along both sides of the thickened portion extends the vitelline gland 
in the form of two dusky longitudinal bands; the mouth, in the form of a 
narrow oval slit, is situated on the ventral surface near the anterior — 
extremity. ‘The pair of anterior suckers—one on each side of the mouth— 
observed in some species of Octobothriwm, were apparently absent in 
Octobothriwm leptogaster. 
The posterior suckers (or bothiia) are transversely and broadly ovate, the 
width being nearly equal to one and a half times the length; they are each 
furnished with about five spines: one springs from the anterior margin and, 
extending across the middle, divides the sucker into two nearly equal parts; 
the others are lateral and occur in pairs—two on each side; the smaller spine 
is nearly straight, but the larger is incurved and hook-like. 
The egys are of an oval shape, widest in the middle; width equal to about 
half the length, horn-coloured, and semi-transparent ; length about 0-2 mm.; 
one end is produced mto a short beak from which springs an exceedingly 
long and extremely slender colourless filament; the other end is without an 
appendage of any kind. 
The entire length of the specimen represented by the drawing is 39 mm. 
The neck and body are marked by numerous faint transverse lines. 
Habitat.—Parasitic on the gills of Chimera monstrosa captured in the 
North Sea in January, 1910; apparently not very rare. 
Genus Aine, Abildgaard, 1795(4). 
In this genus the posterior suckers are small and numerous. 
Agine bellones, Abildgaard. Pl. VII., figs. 6-7. 
1794. Aaine bellones, Abild., Skift. af Naturhist. Selskab., t. ii1., 
p. 59, tab. vi., figs. 3a, b. 
1836. Heteracanthus pedatus et sagittatus, Diesing, Nov. Act. 
Nat. Cur., vol. xvili., 1., p. 310, tab. xvn. 
1850. Axine bedlones, Diesing, Syst. Helminth, vol. 1, 
. 425. 
1858. Axine bellones, P.-J. van Ben., Bull. de Acad. Roy. de 
Belg., vol. xxiil. 
1858. Axine bellones, P.-J. van Ben., Acad. des Sci., Suppl. aux 
Comptes rendus, t. 11., p. 53. 
1863. <Axine orphit, P.-J. van Ben. and Hesse, Rech. sur la 
Bdellodes ou Herudinées et les Trématodes, p. 116, Pl. xu., 
figs. 19-27. 
Body flat, thin, elongated; anterior extremity very attenuated, but 
becoming gradually wider towards the posterior end; posterior extremity 
expanded so as to assume the form of a hatchet (‘“‘hache”). The anterior 
end has the apex pointed, but it may also by contraction become emarginate 
(fig. 7). The mouth opening is denticulated and provided with two lateral, 
oval, and denticulated suckers. The genital aperture is of medium size and 
furnished with fasicles of minute teeth or hooks arranged partly vertical 
