NOTES ON THE MARINE OLIGOOHiETA OP PLYMOUTH. 71 



and lead me to infer its identity with d^Udekem^s Tuhifex Benedii, 

 whicli appears from the woodcut in Udekem^s* paper to possess 

 similar papillae ; this has been already urged by Vaillant. Claparede 

 does not mention the presence of hair-like setae ; these indeed are 

 present in some individuals and absent in others ; when present they 

 exist only in the dorsal fascicles. The only genus of Tubificidae in 

 which this capricious arrangement of the setse occurs is Eisen^s genus 

 Hemitubifex ;f but the only species of that genus is fresh water. 

 Clitellio ater furthermore agrees with Hemihihifex in the dilatation 

 of the termination of the vas deferens connected with the atrium ; I 

 am not, however, convinced that this species is an Hemitubifex, 

 though there does not appear to be any other genus to which it can 

 be unhesitatingly assigned. 



I have already communicated to the Zoological Society of London 

 a fuller account of the anatomy of these two Tubificidae. 



* Loc. cit., p. 544. 



+ Oligochatological Researches, Report of the (U. S.) Commissioners for Fish and 

 Fisheries for 1883. 



