BY J. J. FLETCHER, M.A., B.SC. 553 



in two specimens collected for me in the spring. These specimens 

 have a clitellum of six, or six and a-half segments, commencing 

 with segment xiv or the posterior part of xin, up to and including 

 xix. This region is differently coloured, has its surface modified, 

 but the glandular development not so thick in all cases as to 

 obscure the lines of demarcation between the segments, though in 

 one specimen the clitellum is perfectly complete all round and so 

 thick that it does do so. The ridges and pores are s tuated on the 

 posterior ventral portion of the clitellum. (Fig. 6.) In these 

 worms it appears then that when not actively breeding the 

 clitellum is usually absent. The male pores being on segment 

 xvin, this species also is intraclitellian, and cannot be referred to 

 McCoy's genus Megascolides as at present detined. 



As in the other species the first four mesenteries are incomplete, 

 while most of those from segments vi to xin are excessively thick 

 and strong, with strong interseptal ligaments ; in worms at all 

 contracted, they overlie one another like saucers, and nothing is 

 seen in dissections of the contents of the anterior segments, until 

 they are put aside. The presence of a few enormously thickened 

 anterior mesenteries like these, prevails in all the other worms I 

 have examined, except in our Lumbricus, and in Didymogaster, in 

 both of which it is much less noticeable. A similar arrangement 

 has been described in other worms, and, as Perrier suggests, it is 

 probably of assistance to them in burrowing, especially where the 

 ground is hard. 



The setse are quite inconspicuous even with a lens after 

 removal of the cuticle, and I have not yet satisfactorily made out 

 their arrangement, but from what I have seen I believe there are 

 eight rows arranged as in the preceding species. 



The male pores, as already mentioned, are on xvin ; the two 

 pairs of spermathecal apertures are between segments vn and viii, 

 and viii and ix ; the two oriducal apertures are on xiv, one on 

 either side of and rather close to median line, and not very conspi- 

 cuous. The dorsal pores are intersegmental, and commence after 

 about the 8th or 9th segment. Nephridiopores not discernible. 



