AN ATTEMPT TO CLASSIFY EARTHWORMS. 221 



A. Prostates present. 



a. Spermiducal pores intersegmental, and placed far for- 



wards ; sperm-duct traversing only one somite; clitel- 

 lum on Somites x to xiii. 



Family IV. Moniltgastrid^. 

 Genus 12. Moniligaster. 



b. Spermiducal pores on Somite xvii or xviii ; clitellum 



occupying all or any of the Somites xiii to xviii. 



1. Eight setae per somite, in couples or separate. 



Family V. Eudrilid^e. 



Genera : — 



13. Eudrilus. 



14. Teleudrilus. 



15. Pontodrilus. 



16. Photodrilus. 



17. Microscolex. 



18. Rhododrilus. 



19. Plutellus. 



2. More than eight setse, usually thirty or more, per somite, 

 arranged in a ring. 



Family VI. Perionycid^. 

 Genus 20. Perionyx. 



B. No prostates present. 



1. Spermiducal pores behind Somite xviii, within the area 

 covered by the clitellum. 



a. One pair of sperm-sacs occupying several somites ; 

 eight setae, separate or alternate in some part at least 

 of the body. 



Family VII. GEOscoLECiDiE. 



Genera : — 



21. Geoscolex. 



22. Urochseta. 



23. Diachaeta. 



