1906.] WORMS OF THE THIRD TANGANYIKA EXPEDITION. 217 



the present species with Alluroides pordagei we find that an 

 analogous concrescence would appear to have taken place dorsally ; 

 for in that species the paired spermathecal orifices are placed close 

 together and well to the dorsal side of the lateral setse. The 

 spermathecal pore has a tumid pei'iphery and is very conspicuous. 

 The mcde pores are upon segment xiii. and upon the ventral 

 surface of the body. They are in line with the ventral setee, which 

 are, however, absent upon that segment. These pores also are 

 large and conspicuous. It will be observed that their position 

 difiers from that of the corresponding pores in Alluroides pordagei, 

 which correspond to the lateral setae and not to the ventral. 



Concerning the oviducal pores I am unable to be certain, as I 

 could not distinguish the oviducts themselves. I think, however, 

 that I have detected them lying behind the male pores and in line 

 with thera upon the boundary-line of segments xiii./xiv. 



The alimentary canal of this Annelid was plainly distinguishable 

 throughout its course. I could see no gizzard, but septal glands 

 were obvious. The oesophagus in the ninth segment acquires a 

 coating of brown pigmented cells, which continue to the end of 

 the body. From the ninth segment to the eighteenth inclusive 

 the oesophagus is moniliform. From the nineteenth segment it is 

 less so and somewhat wider. This region I regard as intestine. 

 The transition from one region to the other is abrupt. 



The vascidar system appears to me to be arranged on the simpler 

 plan characteristic of the aquatic families of Oligochgeta. The 

 dorsal, which is the larger, and the ventral vessels are connected by 

 a pair of looped vessels, quite as in e. g. the Tubificidfe. Anteriorly 

 I am unable to say anything about its relations, except that I 

 could not trace the dorsal vessel forward beyond the large 

 intestine and was quite unable to detect the nepkridia. 



The spermatheca is an oval sac which reaches back quite to the 

 end of the ninth segment. 



The atria end posteriorly in oval expansions looking very like 

 spermathecee. There are naturally two of them. They are directed 

 posteriorly to the pores upon the xiiith segment. 



In view of the facts brought forward here upon this new 

 vspecies of Alluroides, I venture to amend slightly the generic 

 definition of Michaelsen and to distinguish the two species 

 as follows : — 



Genus Alluroides Beddard. 



Alluroides Beddard, Quart. Journ. Micr. Sci. vol. xxxvi 

 (n. s.) p. 252. 



Small, slender, aquatic or semiaquaiic Oligochceta with simjyle 

 S-shaped setm arranged in four pairs. Glitellum in neighbourJiood 

 of male pores. Alimentary canal without gizzard or glands. 

 Meganep>hriG with paired nephridia. Sp)ermathecce {or spermatheca) 

 without diverticida ojjening between viii./ix. at or near median dorsal 

 line. Male p)ores on segment xiii. more or less ventral in p>osition. 



