606 OLIGOCHAETA 



This species is quite distinct from the last. It can apparently be distinguished 

 by the fact that the skin does not possess that dark violet colour which is so 

 characteristic of the various species of the genus that I unite here into the species 

 E. eugeniae. Only a single example was investigated by Michaelsen. It seems 

 in nearly all its structural characters to agree with the last species ; the only 

 point in addition to those mentioned in the above diagnosis of the species 

 in which E. pallidus differs from E. eugeniae is in the fact that the two sperm- 

 ducts of one side unite to form a single tube before they enter the spermiducal 

 gland. The bursa copulatrix, although present as in E. eugeniae, is apparently 

 less developed than in that species. It is described by Michaelsen as the slightest 

 rounded elevation of the body-wall. As the peculiar appendices of this bursa — 

 which I have elsewhere compared with sacs for the penial setae — are absent in the 

 present species, it seems that the terminal copulatory apparatus is in a condition of 

 degeneration. 



(3) Eudrilus buttneri, Michaelsen. 



E. Biittneri, Michaelsen, Arch. f. Nat., 1892, p. 256. 



Definition. Length, wo mm. ; Ireadth, ^ mm. ; number of segments, 145. Colour purple 

 above. Bursa copulatrix without appendices. Female genitalia as in E. pallidus. 

 Hah. — Togo, Bismarchburg , W. Africa. 



This species only differs from E. pallidus in the fact that the skin is pigmented ; 

 in all other particulars it appears to agree ■vyith that species, unless the position of 

 the male pores be really different; in E. pallidus these pores are stated to be on 

 the seventeenth segment in line with the ventral setae, in H. buttneri on the border 

 line of segments xvii/xviii, a little above the line of the ventral setae. 



(4) Eudrilus erudiens, Ude. 



E. erudiens, Ude, Z. wiss. ZooL, 189a, p. 71. 



Definition. Length, 22,0 mm.''-; diameter, ^ mm. ; number of segments, 180. Colour pale 

 yellow to brown. Bursa copulatrix loith ^-shaped appendage. Female genitalia as usual. 

 Hah. — Bermvdas. 



This species appears to differ from E. eugeniae by its colour only. 



' These measurements cannot be regarded as very accurate ; the worms were much softened. 



