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MR FRANK E. BEDDARD ON THE ANATOMY OF OCNERODRILUS. 



Vejdovsky [15] considers that there are no valid reasons for retaining this genus 

 within the Lunibriculidse, and points out the resemblance in the genital system to 

 Earthworms. Later Eisen [2] himself takes the same view, and refers Ocnerodrilus to 

 a distinct family. 



It may be considered, I think, quite certain that Ocnerodrilus has no particular 

 relation to the Lumbriculidae. The points in which Ocnerodrilus does agree with the 

 Lumbriculidae are not sufficiently characteristic ; they are as follows : — 



(1) Setae paired, not bifid at their extremities, 



(2) Septal glands present (as in Stylodrilus), 



(3) Nephridia absent in some of the genital segments, 



(4) Atrium lined by a single layer of cells, 



(5) Ova moderately large, 



and a number of other points which are not more conclusive than the above in determining 

 the affinities of the Worm, for they occur in many of the families of aquatic Oligochseta. 



As to Earthworms, it is evidently with my family Cryptodrilidse that Ocnerodrilus 

 shows the greater number of points of resemblance, and particularly with the genera 

 Pontodrilus, Photodrilus, and Microscolex. Its general resemblances to the Crypto- 

 drilidse are as follows : — 



(1) Clitellum (composed of two distinct layers of cells), extending over segments 



XIII-XIX. 



(2) Vasa deferentia (commencing by funnel-shaped orifices in X and XI), opening 



on to the XVIIth segment in common with an atrium, which is long and 

 tubular in form, and is separable into a glandular and a muscular portion. 



The special resemblances to the genera Pontodrilus, Photodrilus, and Microscolex 

 may be gathered from the following Table : — 





Ocnerodrilus. 



Pontodrilus. 



Photodrilus. 



Microscolex. 



Setae, ...... 



Strictly paired. 



In 8 series. 



In 8 series. 



In 8 series. 



Clitellum, ..... 



13-19 



13-17 



13-17 



13-17 



6 pores, 



17 



18 



18 



17 



Dorsal pores, ..... 



















Gizzard, ..... 







Rudimentary. 







Rudimentary. 



Nephridia, ..... 



Commence in 3 ; 

 absent in 10, 11. 



Commence in 15. 



Commence in 14. 



Common in 5. 



Atrium, ..... 



Tubular. 



Tubular. 



Tubular. 



Tubular. 



Penial setae, ..... 











+ 



+ 



Spermatheca, ..... 



One pair in 8, 



Two pairs in 8,9, 



One pair in 8, 



Absent, or one 





no diverticula. 



with diverticula. 



with diverticula. 



pair in 9 with 

 diverticula. 



Typhlosole, ..... 



















Sulmervian vessel, 



















Hearts, ...... 



In 10, 11 



12, 13 



10, 11, 12 



10, 11, 12 



Septal glands, .... 



+ 







+ 







