216 MR. F. E. BEDDARD ON THE OLIGOCH^TE [Mar. 6, 



give of its external and internal oi'ganisation. There will be 

 equally no doubt fi'om the facts which I shall relate that this 

 Tanganyika worm is specifically distinct from A . pordagei. 



Allurokles tangmiyikm is a more purely aquatic species than the 

 type species of the genus ; for it was dredged from about ten 

 fathoms of watei', whereas A. pordagei was found in the mud of a 

 swamp. So far as I am aware, nothing further has been discovered 

 about this genus since the pul^lication of my own paper referi-ed 

 to above *. Dr. Michaelsen has, hov/evert, from a consideration 

 of the facts made known by me, j^laced the genus in a separate 

 family, Alluroididfe. The new species to be described here 

 necessitates no alterations in the family characters as given by 

 Michaelsen, and a very slight change in the generic characters, 

 which will be attended to aftei- the description of Alhiroides 

 tanganyikce . 



This species is a small, slender, rather transpai-ent woi-m, 

 suggestive of a Lumbriculid, and, so far as I can lecollect the 

 latter, not very different in size from Alluroides pordagei. The 

 single specimen is about 30 nnii. long and not more than I'omm. 

 broad in the widest pait of the body (anteriorl}'). It consists of 

 60 segments. The thinness and transparency of the woi-m, when 

 viewed as a microscopic o1)ject, is distinctly that of a Limicolous 

 Oligocluete. 



The prostomium is rathei- long and pointed ; it is divided by a 

 constriction into an anterior and posteiioi- half. It is longer than 

 the fii'st segment of the body, but is hardly to be separated fi'om 

 it doi'sally. The first-marked constriction on the body sej^ai'ates 

 the first two segments from each other. 



The seta} are plain and of the ordinary pattern without a cleft 

 extremity. They are strictly paired and present upon all the 

 segments of the body with the exception of the fii'st and that which 

 bears the male pores, where the ventral paii- are absent. 



The boundaries of the clitellum were not distingviishable. 



There is no external p)^nis, but the jmrtial immaturity of the 

 specimen may be the cause of this. I only use it doubtfully 

 therefore as a specific character. 



It is mainly by reason of the position of t\\e generative aperti'res 

 that I place this species unhesitatingly in the genus Alluroides. 

 The most anterior of these is a single widish apertuie upon the 

 boundaiy-line of segments viii./ix. The worm is sufficiently 

 transparent to allow it to be seen that tliis oidfice is continuous with 

 a closed thick-walled sac, which seems to me to be obviously the 

 spermatheca. The main fact to be considered about the sperm a- 

 thecal pore is that it is single and doi'sal median in position. I 

 believe that this state of affairs is unique. We find, however, 

 frequent cases of the coalescence of two ventral pores to form one 

 medianly situate ventral pore and a fuithei- coalescence of two 

 speimathecfe, oi-, it may be, the disappearance of one. In comparing 



* See also 'A Monograph of the Order OligochiBta ' (Oxford, 1895), p. 224. 

 t OligochaBta in 'Das Thierreich ' (Berlin, 1900), p. 106. 



