ZooL.— Vol. II.] EISEN-OLIGOCH^TA. 239 



This species is readily distinguished by its two pairs of 

 spermathecse and three pairs of prostates, as well as by the 

 absence of specialized penial setas. The arrangement of 

 the nephridia is also characteristic. The male pore is equa- 

 torial, while, in D. Ribaucourti \\. is intersegmental. 



Detailed Description. 



The single specimen at my disposal was poorly preserved 

 in alcohol and contained much sand. It was first halved 

 and washed free from sand, after which one half was sec- 

 tioned lengthwise. The specimen is not adult and the cli- 

 tellum is not indicated. All other organs were, however, 

 fully developed, with perhaps the exception of the prostates, 

 mention of which will be made later. 



Somites. — The prostomium and somite I are small but 

 normal. From somite XI anteriorly the somites are much 

 smaller. Somite XVII is somewhat larger than those 

 adjoining. 



SetcB. — The common setae are rather slender and straight 

 and without ornamentation. There are no setse ab in XVII 

 and XVIII, but there is at least one seta at the prostate 

 pores in XIX. These setcc are possibly a trifle more slender 

 than the ordinary ones but cannot be considered as penial 

 setse. All the setae are closely paired and all ventral. The 

 ventral interval is one-third greater than the interval b-c. 



Se^ta. — The septa are remarkable for their thinness. In 

 no other earthworm have I found the septa so thin, most of 

 them being only one or two strands thick. The thickened 

 septa are thickened principally along the dorsal and ventral 

 sides. There is no trace of septal glands nor of any sub- 

 pharyngeal glands, but the suprapharyngeal glands are fully 

 developed. 



Intestine. — The two gizzards are powerfully developed 

 and are not particularly characteristic. The tubular intes- 

 tine is straight. In somites XV to XVI there are as usual 



