ZooL— Vol. II.] RISEN— OLIGOCH^TA. l6g 



Key to the Subgenera and Species of Diplocardia. 



I. Spermiducal pores in somite XXI. No penial setas. 



Aleodrihis Eisen. 



1. Keyesi (Eisen). 



II. Spermiducal pores in somite XX. 



Oniahania, subgen. nov. 



2. verrucosa Ude. 



III. Spermiducal pores in XIX. 



Diplocardta Garman (sens. str.). 



a. Spermathecae two pairs. 



3. Both pairs of spermathecal pores are posterior to setae or pre- 



septal; sexual spermathecal setae in VIII and IX. 



Eiseni (Michaelsen). 



4. The pair of spermathecal pores in VIII is postseptal; the pair in 



IX is preseptal; sexual spermathecal setae in VIII and IX. 



Michaelseni Eisen. 



5. Both pairs of spermathecal pores are postseptal; sexual sperma- 



thecal setae in VIII, IX and X Udei Eisen. 



6. Both pairs of spermathecal pores are postseptal; no sexual sperm- 



athecal setae riparia Smith. 



b. Spermathecae three pairs. 



7. Penial setae straight, about one-half longer than ordinary setae. 



Sperm-ducts are hidden in the body-wall. 



communis Garman. 



8. Penial setae sigmoid, several times longer than ordinary setae. 



a. Penial setae not ornamented. Color dark brown. 



singularis (Ude). 



b. Penial setae ornamented. Color pink. 



singularis caroliniana, subsp. nov. 



IV. Spermiducal pores in XVIII. 



Naillenia, subgen. nov. 



9. Spermathecae two pairs. Their pores postseptal, in VIII and IX. 



Sexual spermathecal setae in IX. 



Koebelt, sp. nov. 



