69 Part III — Twenty -eighth Annual Report 



Octobothrium leptogasier, Leuckart. PI. VII., figs. 2-5. 



1842. Octobothrium leptogasier, Leuckart, Zool. Bruchst., vol. iii. 

 p. 25, PI. I.., fig. 5; PL II., fig. 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 Octobothrium, were apparently absent in 

 Octobothrium leptogasier. 



The posterior suckers (or boihria) 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 eggs 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 into 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 Axine, Abildgaarcl, 1795(4). 

 In this genus the posterior suckers are small and numerous. 

 Axine bellones, Abildgaard. PI. VJI., figs. 6-7. 



1794. Axine bellones, Abild., Skift. af Naturhist. Selskab., t. iii., 



p. 59, tab. vi., figs. 3a, b. 

 1836. Heter acanthus pedatus et sagittatus, Diesing, Nov. Act. 



Nat. Cur., vol. xviii., i., p. 310, tab. xvii. 

 1850. Axine bellones, Diesing, Syst. Helminth, vol. i., 



p. 425. 

 1858. Axine bellones, P.- J. van Bee., Bull, de TAcad. Roy. de 



Belg., vol. xxiii. 

 1858. Axine bellones, P. -J. van Ben., Acad, des Sci., Suppl. aux 



Comptes rendus, t. ii., p. 53. 

 1863. Axine orphii, P.- J. van Ben. and Hesse, Rech. sur la 



Bdellodes ou Herudinees et les Trematodes, p. 116, PI. xii., 



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 



