480 WILLIAM NICOLL. 



Steringotrema divergens (Piud.). 

 Odhner, 1911, p. 103. 



This species was met with in fairly large numbers on two occasions 

 (loth and 24th June, 1910) in Blennius ocellaris. It has hitherto 

 only been recorded from the Mediterranean Sea and only in this 

 host. 



Compared with Odhner's description the ventral sucker in my speci- 

 mens is less anisodiametric. The ratio of the two diameters being 6 : 7 

 instead of 6 : 8. The oesophagus is more contracted and wider, while the 

 intestinal diverticula do not reach the middle of the testes. The ovary 

 shows slight indentation, oiving it a somewhat indistinctlv trilobate 

 appearance. 



Steringotrema pagelli (van Beneden) (Fig. 2). 

 Odhner, 1911, p. 102. 



A few specimens of this species were collected from the intestine of a 

 sea-bream {Sparus centrodontus) obtained from Bilhngsgate Market, 

 London (19th June, 1912). It was not possible to ascertain whether the 

 fish was captured in the North Sea or in the Enghsh Channel. When 

 collected the specimens were already dead and somewhat macerated. 

 They were of a dull grey colour and remarkable for their great 

 thickness and the unusual size and prominence of the ventral 

 sucker. 



The specimens measure 3-6-4-1 mm. in length \\'ith a greatest breadth 

 of 1-6-1 -8 mm. Both ends of the body are pointed. The oral sucker, 

 which in every case is elongated, measures about -48 x -39 mm. in a 

 specimen 3-8 mm. long. The ventral sucker, circular or transversely 

 oval in outhne, measures 1-05 X 1-16 mm., so that the ratio is not quite 

 as much as 3 : 1. The distance of the centre of the ventral sucker from 

 the anterior end is about 1-8 mm. ; it thus lies a little in front of the 

 middle of the body. 



The pharynx has a diameter of -17 mm., and the oesopbagus is somewhat 

 longer. The intestinal diverticula diverge widely. Their ends are 

 obscured by the great mass of ova. 



The ovary and testes are also almost completely hidden by the uterus. 

 The cirrus-pouch is a long bulbous structure lying immediately in front 

 of the ventral sucker, which it touches. The aperture is on the level of 

 the intestinal bifurcation and about midway between it and the left 

 margin of the body. The vesicula seminahs is of comparatively large 

 size. 



