1892.] 



AaUATIC OLIGOCHJETOUS WORMS. 



357 



Genital segments of Kerria halojMIa, as seen on a dissection. 



&, Q-iazard ; Ca, calciferous glands ; Sp, spermatotheca ; T, testis ; Sp.d. sperm- 

 ducts ; 0, ovary ; Od, oviduct ; At, atrium. 



Segments of clitellum indicated in Eoman numerals. 



