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



give of its external and internal organisation. There will be 

 equally no doubt from the facts which I shall relate that this 

 Tanganyika worm is specifically distinct from A. 2>orclagei. 



Alluroicles tang any ikce is a more purely aquatic species than the 

 tyj)e species of the genus ; for it was dredged from about ten 

 fathoms of water, whereas A . j)ordagei was found in the mud of a 

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

 about this genus since the publication of my own paper referred 

 to above*. Dr. Michaelsen has, howeverf, from a consideration 

 of the facts made known by me, placed the genus in a separate 

 family, Alku^oididee. 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 AUuroides 

 taynganyikm. 



This species is a small, slender, rather transpai'ent worm, 

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

 latter, not very different in size from AUuroides j)ordagei. The 

 single sjDecimen is about 30 nnn. long and not more than 1"D mm. 

 broad in the widest part of the body (anteriorly). It consists of 

 60 segments. The thinness and transparency of the worm, when 

 viewed as a microscopic object, is distinctly that of a Limicolous 

 Oligocheete. 



The jyrostommm is rather long and pointed ; it is divided by a 

 constriction into an anterior and posterior half. It is longer than 

 the first segment of the body, but is hardly to be separated from 

 it dorsally. The first-marked constiiction on the body separates 

 the first two segments from each other. 



The setce are plain and of the ordinary pattern without a cleft 

 extremity. They are strictly paii-ed and present upon all the 

 segments of the body with the exception of the first and that which 

 bears the male pores, where the ventral pair are absent. 



The boundaries of the clitelluin were not distinguishable. 



There is no external penis, but the partial immaturity of the 

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

 therefore as a specifi c character. 



It is mainly by reason of the position of tlie generative apertures 

 that I place this species unhesitatingly in the genus AUuroides. 

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

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

 transparent to allow it to be seen that this orifice 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 sperma- 

 thecal pore is that it is single and dorsal median in position . I 

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

 frequent cases of the coalescence of tvv^o ventral pores to form one 

 medianly situate ventral pore and a further coalescence of two 

 spermathecfe, or, it may be, the disappearance of one. In comparing 



* See also 'A Monograph of the Order 01ia:ocha3ta ' (Oxford, 1895), p. 224. 

 t Oligochajta in 'Das Thierreich ' (Berlin,"l900), p. 106. 



