STETJCTURE OF TWO NEW CtENERA OF EARTHWORMS. 253 



the compartment of the egg-sac are associated with a few 

 germinal cells, which are generally closely attached to the 

 ovum, and frequently show signs of degeneration. The masses 

 of immature germinal cells and ova, in all stages of develop- 

 ment, which I have figured and described in Eudrilus (2) 

 are not to be found in the present genus. 



II. — Heliodrilus lagosensis, nov. gen., n. sp.^ 



Among a number of earthworms which arrived in a Wardian 

 case at Kew Gardens from Lagos, West Africa, was a single 

 specimen which I refer to a new genus, belonging, like Hy per i- 

 odrilus, to the family Eudrilidce. 



§ External Characters. 



It is of about the same size and colour as Hyperiodrilus, 

 but the external characters of the specimen when killed and 

 preserved are quite unlike those of the former species. 



The prostomium is of the same form as that of Hyperio- 

 drilus. 



The setsB have precisely the same arrangement as in 

 Hyperiodrilus — that is to say, the ventral couple are at some 

 little distance from each other, while the lateral couple are very 

 closely approximated. 



The clitellum was not very distinctly marked, but appeared 

 to comprise four segments, 14 — 17. 



Dorsal pores could not be detected. 



The nephridiopores are placed in front of the lateral setse. 



The ovi ducal pores, as in all Eudrilidae, are lateral in 

 position ; they are upon the 14th segment, and are quite con- 

 spicuous, owing to their being surrounded by a slightly raised 

 margin. 



The male generative pore is unpaired and median in 

 position ; it lies upon the border-line between Segments 17 and 

 18 : the pore is situated upon the summit of a prominent 

 elevation. 



> The generic name might be confused with Helodrilus if there were 

 any chance of that problematical form ever being properly identified. 



