202 W. B. BENE AM. 



rier,i and later of Beddard^ Horst, Kosa^ myself, and others, 

 have shown that, of these four characters, only the last can be 

 retained ; and at the same time numerous points of agreement 

 between " Limicolse " and " Terricolfe " have been brought to 

 light, especially by the help of microscopic research. For 

 example, Beddard has pointed out the similarity between the 

 genital organs of the earthworm Moniligaster and the 

 water- worm Stylaria. 



From his observations of the various specimens of earth- 

 worms in the Paris Museum^ Perrier suggested a subdivision 

 of the "Terricolse" into four groups: (1) Antecliteilian ; 

 (2) Intraclitellian ; (3) Postclitellian ; and (4) Aclitellian. 



Beddard and Horst have already shown that the second and 

 third of these names cannot be always applied to all species of 

 the same genus, one species being Intraclitellian, others 

 Postclitellian ; and A. G. Bourne" has described a species of 

 Moniligaster, for which the fourth group was formed, in 

 which a clitellum is present. 



Vejdovsky,^ in his beautiful monograph on the Oligochgeta, 

 divides the members of the group into seventeen families, each 

 of equal value. These are — 



Family 1. Aphanoneura. 



2. Naidomorpha. 



3. Chsetogastridse. 



4. Discodrilidae. 



5. Enchytrseidse. 



6. Tubificidse. 



7. Phreoryctidae. 



8. Lumbriculidse. 



9. Pontodrilidse. 



10. CriodrilidEe. 



11. Lumbricidae. 



12. EudrilidEe. 



' Perrier, " E.ech, pour servir a, I'bist. des Lombricicns terreslres," 'Nouv. 

 arch, du Mus. d'hist. iiat. dc Paris,' t. viii, 1872. 

 » A. G. Eouriie, ' Proc. Zool. Soc.,' ISSG. 

 ' Vejdovsky, •' S^-steme uiid Morphologic der Oligochaelcu,' Prag., 1884. 



