M. V. JjKbouh 
441 
to the sides of the pharynx. Ventral sucker at about the centre of the 
body, the same size or slightly smaller than the oral sucker. Large 
unicellular stylet glands at the sides of the ventral sucker opening by 
four long ducts near the oral sucker. A stylet was not seen but 
possibly there may be a very small one as these glands seem to indicate 
its presence. Another pair of glands just in front of the ventral sucker 
with long ducts are probably cystogenous glands. The very large 
excretory vesicle is oval and lined by large cells like those of the 
stumpy-tailed cercariae. This cercaria is very like the cercaria of 
Allocreadium isoporum Looss (1894, p. -54) which is developed in 
rediae in Cyclas. This has an enormous tail, eye-spots, prepharynx, 
pharynx and alimentary canal, conspicuous glands in the front part of 
its body. It is to be noted that the adult of this species has large 
unicellular glands (“ head glands ”) opening near the oral sucker by 
long ducts. There is however an indication in Looss’ figure of a stylet 
in the oral sucker of the cercaria. 
It is just possible that Cercaria nepttineae may be the larval form 
of an Allocreadium or Lebouria Nicoll. 
The further life-history is not known in any way. 
(b) Acanthopsolus group. 
Genus Acanthopsolus Odhner. 
Acanthopsolus lageniformis mihi (1910, p. 29). 
(PI. XXVIII, figs. 3-6.) 
Occurs in rediae in the digestive gland of Buccinum undatum in 
seven per ceirt. of those brought in by the Cullercoats fishing boats. Also 
it was found once in a specimen of Buccinum undatum from Holy Island. 
The rediae are of various sizes, the older specimens being a pale 
yellowish. The smalle.st seen were about 0'30 mm. long and had no 
collar nor ambulatory appendages, hind end is pointed, pharynx and 
intestine conspicuous. These small rediae coirtained no cercariae. 
Larger specimens measuring from 0’50 mm. contained them, the in¬ 
testine hardly growing at all, untd in the large rediae of about 3 mm. 
it is so small that it can be easily overlooked. There may be 30 or 
more cercariae in each redia. 
The young cercaria has a tail but it apparently loses it just before 
it is ready to emerge frour the redia and in all probability there is no 
Parasitology iv 29 
