232 Procecdinrjs of the Roycd Physical Society. 



generally not clear in the parasites — the indication of a 

 cellular composition." 



Correlated with the absence of muscular tissue in the 

 oesophagus is an absence of cuticular teeth. 



The second division of the alimentary canal — the intestine 

 — is marked off from the oesophagus by a sharp constriction, 

 and by a difference of tissue, which is shown by the different 

 way in which the staining reagent has acted upon it. The 

 cells are nucleated and of an oblong shape, and contain 

 numerous granules ; they are arranged in a single layer round 

 the lumen of the tube. The diameter of the intestine is 

 hardly more than half that of the oesophagus. 



The terminal part of tlie alimentary canal is only to be 

 distinguished from the intestine by its greater calibre, and 

 strongly marked cuticular lining. It extends in the female 

 from a point considerably anterior to the generative opening, 

 the precise position of which it was impossible to determine, 

 owing to its being covered by the coils of the generative 

 tube. In the posterior third of the body, the alimentary 

 canal becomes wider still, and, at the extreme end, under- 

 goes a further dilatation, and opens to the exterior by the 

 ventral anus which is situated some way in front of the two 

 suckers (Fig. 1). 



Scattered throughout the body, and lying apparently in 

 the perivisceral cavity, are a quantity of round bodies, which 

 look like oil globules. I could only find them in the female, 

 where they exist in great numbers, especially in the tail and 

 the hinder part of the body (Figs. 1, 5). They may be the 

 contents of some of the eggs which have got broken. 



The generative organs conform to the type that is gene- 

 rally found in the parasitic Nematoids. The ovarian tube 

 commences between the suckers, and runs forward nearly as 

 far as the hinder end of the oesophagus ; it is then bent upon 

 itself, and coiled several times, and opens by a wider terminal 

 portion, which contains fully formed eggs in various stages of 

 development, and corresponds to a vagina. The generative 

 aperture is situated about the middle of the body. In the 

 male the testicular tube commences about the end of the 

 anterior third of the body, and after running forward for a 



