452 WILHELM MIOHAELSEN. 



20 b. Clitelluui extends from the thirteenth to the seventeenth 



segment, but often incomplete on the thirteenth and 

 seventeenth segments, or on one of them. 



Chilota warreni;-*?,. sp. 



21 a. Seta; all ventral in position, median dorsal distance dis- 



tinctly larger than half the circumference of the body. 



Dichogaster bolaui Mich. 



21 b. Outer pairs of setae lateral in position ; median dorsal dis- 



tance eqiial to half the circumference of the body. 



Kerria gunningi [Mich. 



22 a. Set* separated ab < fee < cd. Prostate pores paired at 



the eighteenth segment. 



Pontodrilus bermudensis Bedd. f . typicus 



22 b. Setse strictly paired. . . . ,23 

 23 «. Prostate pores paired at the seventeenth segment. 



Spermathecal pores paix-ed at the furrows l^etween the 

 seventh and eighth segments and the eighth and ninth 

 segments, or at one of them. . . .24 



23 fe. Prostate pore and spermathecal pore single and median 



at the seventeenth and thirteenth segments respectively. 

 Paired copulatory papillse at the eleventh, thirteenth, 

 and fifteenth segments. . E u d r i 1 o i d e s d u r b a n e n s i s Bedd. 



24 a. Seta? are all ventral in position ; median dorsal distance 



distinctly larger than half the circumference of the 

 body. Two pairs of spermathecal pores. 



Dichogaster crawi Eisen. 

 24 b. Outermost pairs of setaj lateral in position ; one pair of 

 spermathecal j^ores at the furrow between the eighth 

 and ninth segments. . Ocnerodrilus af ricanus {Bedd.) 



B. KEY FOUNDED ON INTERNAL ANATOMY AS WELL AS EXTERNAL 



CHARACTERS. 



1 a. Minvite white or dirty grey worms, not longer than 20 mm., 

 less than 1 mm. in diameter. Male papilte at the 

 twelfth segment, clitellum extending from the twelfth 

 segment into the neighbouring eleventh and thirteenth 

 segments. No muscular gizzard. (Fam. Enchytraiidaj, 

 gen. Fridericia). .... 2 



1 b. Larger worms at least 20 mm. long, and thicker than 1 mm. 

 Male papillae further back than the twelfth segment. 

 Clitellum occupies at least three complete segments, 

 including the sixteenth segment, if not beginning 

 further back (real earthworms). . . 3 



