BY S. J. JOHNSTON. • 343 



flat spines or scales, which have their free ends bluntly round- 

 ed and directed posteriorly (Fig. 80). Each scale is 001 mm. 

 broad at its base, and 001 mm. long, and the rows are 0-01 

 mm. apart all over the body. At the posterior end, the scales 

 are a little shorter, and not quite so close-set. 



The pharynx is globular, 0065 mm. in diameter, with thick 

 mviscular wall ; the oesophagus is narrow, but fairly thick - 

 walled, and moderately short. The limbs of the intestine are 

 short, reaching the level of the middle of the testes. That 

 on the right, running ventral to the ovary, ends between it 

 and the right testes. 



The excretory vesicle (Fig. 77) is V-shaped, with wide limbs 

 which stretch forward, and end just behind the testes ; the 

 pore opens at the posterior end, and is exactly terminal. 



The testes are comparatively large, 0-43 mm. long, by 0193 

 mm. broad, more or less oval in form. They lie right up to 

 the lateral edges of the body (Fig. 77), and just in front of 

 the ventral sucker. The vasa deferentia run straight in- 

 wards, and join the vesicula seminalis, which is a coiled, wide 

 tube lying in the base of the cirrus-sac. The cirrus-sac, which 

 lies altogether in front of the ventral sucker, and mainly in 

 front of the testes, is a large, somewhat S-shaped structure, 

 wide behind, but narrowed in front ; there is a conpicuous 

 pars prostatica, and well-marked ejaculatory duct and penis. 

 The common genital opening lies on the lateral edge of the 

 body, alongside the oral sucker (Fig. 78). 



The ovary is pear-shaped, with the narrow end directed 

 backwards ; it lies on the right side, partly in front of the 

 right testis, but more dorsal and nearer the middle longitudi- 

 nal line of the body. The oviduct is given off from the 

 narrow end, and runs directly backwards : very soon it widens 

 slightly to form the ootype, and it is here surrounded by a 

 thick mass of the large cells forming the shell-gland ; and 

 at this level, about opposite the middle of the testes, a com- 

 paratively large receptaculum seminis and Laurer's canal are 

 given off. Laurer's canal is short and narrow, and opens 

 on the dorsal surface, and opposite the anterior edge of the 

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