THE TREMATODE PARASITES OF FISHES. 475 



The ovary lies to the right of the anterior testis and a little in advance 

 of it, the two being almost contiguous. It is a distinctly trilobate body, 

 the lobes being directed backwards, and its greatest diameter is -13 mm. 

 It is separated from the ventral sucker by a space of -14 mm. The 

 medium-sized, pear-shaped receptaculum seminis lies immediately in 

 front of the anterior testis. The yolk glands are moderately developed. 

 They are almost entirely marginal, their anterior limit being the level of 

 the ventral sucker. They fill up a considerable part of the post-testicular 

 space, but do not unite. Behind the ovary a few follicles are found on 

 the inner side of the right intestinal diverticulum, while on the left a few 

 are found internal to the diverticulum on the level of the posterior testis. 

 The scanty ova measure •069--072 x -036 mm., and are provided with a 

 minute knob-like process at their anopercular pole. 



In referring this form to the genus Podocotyle rather than to any of 

 the other genera of the sub-family one is influenced by the characteristic 

 shape of the ovary, the position of the genital aperture and the length 

 of the cirrus-pouch. The position of the testes is the chief contradictory 

 feature, and in this respect the species bears a closer resemblance to 

 Lebouria. It might be suggested that it is an abnormal specimen of 

 P. atomon in which the testes have become displaced, but as I have no 

 previous experience of such an abnormality I am very doubtful if this 

 could be the case. 



Genus LEBOURIA Nicoll. 



Lebouria alacris (Looss). 



Nicoll, 1910, pp. 332-4. 



This species was frequently obtained from the smaller Labridae 

 {Ctenolahrus rupestris,*Centrolahrus exoletus and Crenilabrus melops). A 

 single specimen was also found in the intestine of Labrus hergcjyJta. 



Lebouria varia Nicoll. 

 Nicoll, 1910, pp. 329-32. 

 This species was only met with in the dragonet {CaUionymus lyra), in 

 which it is fairly common. 



Genus PERACRBADIUM Nicoll. 



Peracreadium commune (Olsson). 



Nicoll, 1910, pp. 328-9. 



Only three specimens of this species were met with in Labrus berggylta 



and Crenilabrus melops. They agree with my previous description, except 



