1888.] 



STRUCTURE OF CLITELLIO. 



491 



therefore that I should have the pleasure of recording for the first 

 time the presence of oviducts iu the Tubificidae, and finally exploding 

 the very improbable hypothesis that in these worms the penis-sheath 

 is the liomologue of an oviduct. I find, however, that Dr. Stole has 

 already ' demonstrated these organs in Ilyodrilus and Psammoryctes ; 



Fig. B. 



Genital segments of CUteHio arenarius. The atrium of the right side and the 

 left spermatheca have been removed, t, testes ; /, vas deferens funnel ; 

 d, male genital orifice ; a, ovary ; oc, oviduct ; cf, spermatheca, containing 

 spermatophores ; o, ripe ova in egg-sacs. 



my own discovery of the oviducts occupying an identical position 

 in Clitellio and in Hemitubifex ater (=CliteUio ater, see below 

 p. 494) lends further support to Dr. Stoic's contention that these 

 organs will be found to be invariably present in the Tubificidae. 



The ovaries are situated in the 11th segment on the anterior 

 mesentery, close to where this is perforated by the vas deferens. 

 » Zool, Anzeig. Bd. viii. d. 660. 



