36 



' TERRA NOVA " EXPEDITION. 



smooth ovary (ov) 0'22 mm. The eggs are few in number but of very considerable 

 size, and have a brown shell measuring 0 - l mm. by 0"03 mm. while still within the 

 body. 



ALLOCREADIINAE. 



Podocotyle, Dujardin, 1845. 



10. Podocotyle pennelli, Leip. and Atk. (PI. Ill, fig. 19). 



Podocotyle pennelli, Leiper and Atkinson, Proc. Zool. Soc, 1914, p. 224. 



Small forms tapering from the large pouting ventral sucker. The armed cirrus extends to the 

 posterior level of the ventral sucker. Yolk-glands large and discrete. Testes smooth, tandem. Eggs 

 large, with a flat knob-like protrusion at one pole. 



Host. — About six members of this species were obtained from Trematomus 

 bernacchii. 



Parasite. — The specimens vary in length from 2 '4 mm. to 2 "8 mm. The greatest 

 transverse diameter of the body is in the region of the large fleshy ventral sucker, 

 from which the body tapers markedly in both directions. The skin is smooth. The 

 position of the ventral sucker (PI. Ill, fig. 19, l>) varies ; the posterior portion of the 

 body may elongate so that the sucker appears to be situated in the anterior third, in 

 other cases the sucker is almost in the centre. The oral sucker (a) is a, spherical 

 muscular organ, 0'18 mm. by 015 mm., succeeded immediately by a round pharynx 

 of half its diameter. The gut-branches (g) do not extend quite to the hind end of 

 the body, but end on a level with the posterior limit of the testes. The genital 

 pore (///>) opens midway between the oral and ventral suckers, always considerably to 

 the left of the middle line. The armed cirrus is slightly extended, and can be traced 

 backwards as a sausage- shaped mass to a level just short of the posterior rim of the 

 ventral sucker. The yolk-glands (y, y') are discrete and extensive, ranging from the 

 level of the genital pore to the posterior extremity. The testes (t, f') are smooth oval 

 bodies which vary markedly in size in different specimens. They lie one in front of the 

 other in the intercaecal region behind the ventral sucker ; in front of them and slightly 

 to the right is a large ovary (ov). which may be pear-shaped or very slightly lobate. 

 The eggs are large, 0'06 mm. by 0"04 mm. Each has a distinct knob-like protrusion of 

 the shell-substance at one pole. 



Allocreadium, Looss, 1900. 

 17. Allocreadium fqwleri, Leip. and Atk. (PL III, fig. 21.) 



Allocreadium fowleri, Leiper and Atkinson, Proc. Zool. Soc, 1914, p. 224. 



Immature forms 074 mm. in length, 0'4 mm. broad. Skin smooth. Cylindrical excretory vesicle 

 with fine black pigment-granules. Large ventral sucker 0-36 mm. Three small round bodies, 04 mm. 

 in diameter, represent the genital glands. 



Host. — Trematomus bernacchii. 



Parasite. — A few microscopic Trematodes of a deep red colour occurred with 



