704 MR. F, E. BEDDARD ON NEW [DeC. 20, 



where it passes into the intestine ; the latter tube is ciliated through- 

 out. In the ixth segment a pair of ventrally situated calciferous 

 glands arise from the oesophagus. The lumen of these is much 

 divided ; they are very vascular. 



The circulatory system consists only of tvFo longitudinal trunks — the 

 dorsal and ventral vessels ; I could find neither supra-intestinal nor 

 subnervian. Another pair of longitudinal vessels exist in the anterior 

 region of the body ; these arise one on each side from the free 

 extremity of the calciferous glands, and pass forwards through the 

 septal glands. The last pair of hearts are in segment xi. ; in front 

 of these are two pairs which are equally large. 



The two pair of testes are in x. and xi. ; corresponding to them 

 are two pairs of ciliated rosettes ; the single sperm-duct of each side 

 opens on to the xviith segment, and there are no glands of any kind 

 or penial setse associated with these orifices. One pair of sperma- 

 tothecse open on to the anterior boundary of segment ix. ; they are 

 simple oval pouches without diverticula and were full of sperm. 



The sperm-sacs have an arrangement which is unusual among 

 Earthworms in general and hitherto unknown in this particular 

 family ; they lie in segments ix. and xii., the intermediate segments 

 being occupied by masses of developing sperm unenclosed by any 

 membrane. The sperm-sacs of segments ix. and xii. are attached 

 to the posterior and anterior septa respectively of their segments 

 respectively and are racemose in form. 



The ovaries lie in segment xiii. attached, as usual, to the front 

 septum of the segment ; they lie just above the nerve-cord, but below 

 the ventral blood-vessel, and in the middle line are squeezed almost 

 flat between the blood-vessel and the nerve-cord. In a continuous 

 series of longitudinal sections the ovary of one side is seen to pass 

 into that of the opposite side without any break, though the middle 

 part is rather thinner. This is one of the very few Oligochseta with 

 an unpaired ovary ; ^olosoma is another instance, but in that 

 Annelid the ovary is not plainly made up of two fused halves as it is 

 in the species here described. Quite recently Schneider^ has de- 

 scribed a Rhinodrilus with a single ovary in segment xvii. : in 

 view of the constancy in the position of the ovary, this statement in 

 my opinion requires verification. The ripe ova are invariably sur- 

 rounded by a follicle of relatively considerable thickness ; this follicle 

 has a fibrillated appearance, and there are numerous interspersed 

 nuclei. There were ova, free from the follicle, within the mouth of 

 the oviduct. The oviducts open on to the exterior part in front of 

 the ventral setse. There are no egg-sacs. 



It is clear that this worm should be referred to the family 

 Geoscolecidse, but it is not clear as to which genus of that family 

 it most nearly approaches : in the first place, it should be noted 

 that Ilyogenia is in certain respects a somewhat degenerate form 

 when compared with other Geoscolecidse ; this would in any case 

 render the decision as to its affinities a matter of difficulty. The 



^ "Ueber eine neue Eegenwurm Art auf Trinidad," Dorpat Naturf. Q-es. 

 Jbrg. 18, p. 42. 



