NEW r4ENERA AND SPECIES OF EARTHWORMS. 27S 



is precisely what we find in the two other genera in which there 

 is a penis or are penes. I have pointed out that in Hyperio- 

 drilus these processes of the body-wall may arise from either 

 the 16th or from the 17th segment; in Stuhlmannia 

 variabilis, which has received its name on account of the 

 variability in the position of this organ, Michaelsen has de- 

 picted it as arising from either the 15th or the 17th segment.^ 



The prostomium is conspicuous, and extends for a little way 

 on to the 1st segment. 



The clitellum is developed all round the body, and occupies 

 Segments 15 — 17. In one specimen which I examined, mounted 

 as a flat preparation, there were no setse upon the 17th seg- 

 ment, and only one pair (the ventralmost of each side) upon 15 

 and 16 (see fig. 24). 



§ Internal Anatomy. 



In dissecting the worm the most salient character appears 

 to be the existence of five separate gizzards lying in Segments 

 18 — 22 ; this character, of course, allies the worm to the 

 genera Hyperiodrilus and Heliodrilus; the latter are the 

 only Eudrilids in which the gizzards have this unusual loca- 

 tion ; this fact, indeed, seems to have led Michaelsen to asso- 

 ciate the two into one genus. 



In other respects the alimentary canal of this worm does 

 not show any diflFerences from the alimentary canal of Helio- 

 drilus; there are three ventral pouches in Segments 9, 10, 

 11 ; in Segment 13 are the calciferous glands. The first 

 recognisable septum divides Segments 4 — 5 ; this and the seven 

 following are thicker and stronger than the other septa. The 

 nephridia commence in the 4th segment ; their external aper- 

 tures are in front of the dorsal couple of setse. 



This species diflFers from Heliodrilus lagosensis and 

 from Hyperiodrilus in having no integumental sense-organs, 

 which are found in so many Eudrilidse. This is one of the 



* " Beschreibung der von Herrn Dr. Fr. Stuhlmann auf Sansibar und dem 

 gegeneberliegenden Festlande gesammelten Terricolen," * Jalirb. Hamb. wiss. 

 Anst.,' Bd. ix, »if. ii, figs. 13 and 14. 



