JOURNAL OF TUT; COLLEGE OF 8C1RNCE, TOKYO IMPERIAL UNIVERSITY. 



Vol. XZXVI., Art. 5. 



On the Pelagic Annelids of Japan. 



By 

 Akira Izuka, 



Iiigakushi, ffigakuliaJciishi, 



Frofessor of Zoology, Imperial Peers' College, Tokyo. 



With one plate. 



Introduction. 



Of pelagic Annelids, the Alciopidse and the Tomopteridse, not 

 a single species has hitherto been reported from the Japanese 

 waters, while my own researches thus far have brought to light 

 nine species belonging to the above families. Of these species 

 three Avere found to be new to science. 



The material upon which my studies were based, have been 

 collected by me mostly in Misaki during my repeated visits to 

 the Marine Laboratory of the Science College, Tokyo Imperial 

 University. Collecting was also made at Heda in Prov. Izu and 

 at Miho in Prov. Suruga. 



Here I beg to offer my thanks to Prof. I. Ijima who rendered 

 me much aid in the course of my investigations. 



Family ALCIOPIDAE 



With two large red, highly organized eyes situated on sides of 

 prostomium, which is further provided with 5 tentacles. On each 

 side of body-segment, near base of parapodiurn, lies a wreath-like 



