BY J. J. FLETCHER, M.A., B.SC. 547 



two lateral longitudinal grooves, with sometimes a second faint 

 outer groove on each side ; when everted the anterior extremity 

 more convex, the grooves then curving upwards to the dorsal 

 aspect, producing a ribbed appearance ; the buccal segment only 

 slightly notched, the prostomium extending back on it only for a 

 about J of its width. 



Most of the segments from iv-xiii are wider than in any other part 

 of the body ; the fourth segment is faintly bi-annulate ; the next 

 nine are each divided by a well-marked groove into two principal 

 annuli of which in segments vu to xiii the posterior ones are 

 subdivided into two secondary annuli, and in segments ix-xiii the 

 anterior annuli are similarly but not so completely subdivided ; 

 slight variations may be met with. Behind the clitellum the 

 segments are narrower, and are either bi-annulate, or shew two 

 grooves, one in front of, and one behind the setse. 



Clitellum thick and glandular, comprising ten segments from 

 xiv to xxiii, but occasionally not taking in quite the whole 

 of the first or last of these, complete except for a narrow portion 

 on the median ventral line between the inner rows of setae, but 

 even here the surface of some of the anterior segments is slightly 

 modified but never so much so as to obliterate the inter-segmental 

 grooves as is the case on the rest of it. My specimens were 

 collected in winter ; when the worms are breeding probably the 

 clitellum is even better developed. 



Setse simple, ^shaped with a slight enlargement nearly in 

 the middle, on papillae, arranged in eight longitudinal rows, of which 

 the four inner rows are ventral in position and form two couples, 

 one on either side of, and rather close to the median ventral line : 

 the four outer rows form two couples and are lateral or ventro- 

 lateral in position. The rows of setse of each of the two outer 

 couples are further apart from each other than are those of the 

 inner ones ; all the rows are plainly visible without a lens. 

 Segments after the first setigerous. 



Male pores two, situated on two slight papillae probably more 

 conspicuous in the breeding season, in a line with the intervals 



