AN ATTEMPT TO CLASSIFY EARTHWORMS. 201 



An Attempt to Classify Earthworms. 



By 



W. B. Beubani, B.Sc., 



Assistant to the JodrcU Professor of Zoology, iu University College, 



London. 



Introduction. 



I. Nomenclature. 

 II. Outlines of the classification. 

 III. Characters of the families and 

 genera. 



IV. Table of generic characters. 



V. Index to genera. 

 VI. Phylogeny, 

 VII. Diagrams. 



The hard and fast line between Earthworms and Fresh- 

 water wormSj as indicated by Claparede's terms^ " Terricolse ^' 

 and *' Limicolae/' is gradually becoming less distinct; and as 

 new knowledge in both these groups is acquired we are led to 

 recognise that the plan adopted by Vejdovsky is the more 

 natural one : although I believe that it is possible to arrange 

 the various families into which he divides the Oligochseta into 

 certain groups. 



The anatomical characters which served Claparede as points 

 of distinction between his two groups were drawn from the 

 knowledge of Lumbricus alone. They were (1) the posses- 

 sion of two blood-vessels below the intestine^ the subintestinal 

 and subneural vessels • (2) the presence of nephridia in the 

 genital somites ; (3) the position of the clitellum behind the 

 male apertures j and (4) the presence of a plexus of capillary 

 blood-vessels on the nephridia. The investigations of Per- 

 1 Claparede, "Rech. sur les Oligochetes," 'Mem. de la Soc. de phys. et 

 d'hist. nat. de Geneve,' t. xvi, 1862. 



VOL. XXXI, PART II. NEW SER. O 



