A NEW GENUS OF OLIGOCHiETA. 477 



EUDRILID^.^ 



(1) Male pores one pair, on Segment 17 or 18, within or 

 behind the clitellum, corresponding to the ventral setse. 



(2) Clitellum complete, occupying generally Segments 13 

 (14) -16 (18) = 3—6. 



(3) Setse eight, paired or singly, but always parallel. 



(5) Gizzard (or gizzards") anterior in position. 



(6) Sperm-sacs generally two pairs. 



(7) Prostate and penial setse present. 



The only characters, therefore, which are decisive are (1), 

 (2), and (7). 



Deodrilus agrees with the Eudrilidae in (1) and (7), and 

 it is intermediate between the two in (2). 



But there are other facts in its structure which signify that 

 it combines the characteristics of genera which have been 

 included in the GeoscolecidEe and in the Eudrilidae. The 

 absence of a prostomium is characteristic of certain genera 

 of Geoscolecidse — Urochseta and Diachseta. It is true 

 that Typhseus, which Rosa refers to the Eudrilidae, has no 

 prostomium ;^ but it must be remembered that this genus 

 agrees with Urochaeta, Geoscolex, and Diachgeta in 

 having a single pair of long tongue-shaped sperm-sacs, and 

 only a single pair of sperm-ducts. 



In the absence of setse from the first few segments Deo- 

 drilus resembles a species of Diachseta, of which a descrip- 

 tion has appeared in a recent number of this Journal (1). 



Typhseus appears to have no setse upon the first two 

 segments, but, as stated in my paper upon that worm (6), I 

 am not absolutely certain of the fact. 



The presence of ornamented setae afiines Deodrilus to 

 Rhinodrilus; nothing of the kind is met with in any of 

 Rosa's Eudrilidse. 



1 I may remark that Eudrilus itself does not agree with this definition in 

 all characters. 



2 I add "gizzards" myself, so as to include Perissogaster, &c. 



' Loc. cit., p. 111. This statement requires confirmation, since Bourne 

 has lately described a prostomium in Typhseus Masoni. 



