On 



A New Eehiuroid (Hamingia ijimai) 

 from the Sagami Bay. 



BY 



I. Ikeda. 



(With Plate I). 



In the summer of 1908 I had a good opportunity to study 

 an interesting deep-sea Eehiuroid which was fished by Mr. K. 

 Aoki, in February of 1907, from a 500 fathom basin of Outside Oki- 

 nose in the Sagami Bay. Closer examination has revealed that the 

 animal is undoubtedly a new form belonging to the genus Hamingia, 

 a genus characterized by sexual dimorphism like the sister genus 

 Bonellia. Only two species have been described in Hamingia, viz., 

 H. arctica Danielsen et Koren 1 and H. sibogac Sluiter.'" {H. glacialis 

 Horst, :! described from two specimens collected by the " Willem 

 Barent," was later proved to be identical with H. arctica). It may 

 here be noted that the two species have been obtained from locali- 

 ties widely separated and from different depths ; H. arctica was 

 obtained in comparatively shallow waters of the Arctic sea (a few 

 hundred miles north of North Cape) and of Hardangcr Fjord, 4 while 

 H. sibogac came from an abyssal depth (4391 metres) of the Banda 



1. Danièlsen, D.C., and Koren, J., — The Norwegian North Atlantic Expedition, 1S76— 

 1S7S; Gephyrea (Zoology), 1SS1 , Christiania. 



2. Sluiter, C. Ph., — Die Sipunculiden und Echiuriden der Siboga Expedition (Siboga 

 Expeditie, XXV, 1902). 



3. Horst, R., — Die Gephyrea gesammelt während der zwei ersten Fahrten des "Willem 

 Barent" (Niederländ. Archiv für Zoologie, Suppl. Bd. 42 1SS1). 



4. Lankester, E. R., — On Specimens of the Gephyrean Hamingia arctica Kar. and Dan. 

 from the Hardanger Fjord (Ann. and Mag. of Nat. Hist, 5, XI, 1883). 



