STUDIES ON EAETHWORMS. 77 



Studies on Earthworms. No. II. 



By 



1¥illiani Blaxland Benbam, B.Sc, 



Demonstrator in the Zoological Laboratory of University College, London. 



With Plates VIII and IX. 



In continuation of Part II of my previous paper on this 

 subject,^ I shall describe three new genera belonging to 

 Perrier^s group of Intraclitelliani. Although Beddard has 

 shown^ that the grouping of Earthworms according to the rela- 

 tive position of the male pore and the clitellum, does not hold 

 good even within the limits of one genus, yet it is a convenient 

 classification, and, I think, may be used at present till a more 

 satisfactory system is introduced. The genus Acanthodrilus 

 to which I refer is post-clitellian in most of its species, but 

 Beddard describes A. novae-zelandiee and other species as 

 having the male pore situated in the clitellum. 



I have received all the worms which I am about to describe 

 from Prof. Ray Lankester, who has for many years taken every 

 opportunity of procuring exotic specimens. The new genera 

 show interesting combinations in one worm of characters which 

 have been regarded as of generic value for different worms : 

 thus Urobenus possesses intestinal glands known hitherto 

 only in Urochaeta, and also cseca similar to those which are 

 known only in Perichaeta. Again Trigaster combines an 

 alimentary tract somewhat like that of Digaster, with the 

 four prostates and male pores of Acanthodrilus. 



Since writing my previous paper onMicrochaeta I have 



1 This Journal, February, 1886, p. 213. 

 ' 'Proc. Zool. Soc.,' 1885, p. 810. 



