NOTES OX A DEEP-SEA ECHIUEOTD. 143 



extending between the roots both of the dorsal and the neuro- 

 intestinal vessels. 



The single oviduct {od., fig. 9) is situated on the right side 

 of, and very close to, the ventral nerve-cord {v. n.) It is a 

 comparatively small tubular sac, measuring about 10 mm. 

 in length, and consists of four parts ; the narrow and highly 

 muscular neck, the swollen glandular part, the thin-walled 

 reservoir, and the stalked funnel. As is the case with 

 Hamingia ijimai, the funnel, which is fimbriated in its 

 margin, springs from the very beginning of the reservoir. 

 There were no egg-cells, either in the interior of the reser- 

 voir or in the glandular part. The female gonad also was 

 not found either on the ventral vessel or at any other place. 



This concludes the account of the anatomy of the female. 

 Lastly, a few words must be devoted to the parasitic males, 

 four of which were picked out of the glandular part of the 

 oviduct of the female. With regard to the three whole males, 

 one was broken to pieces while being removed They are 

 3-8-4-2 mm. long and about O'lo mm. thick (at the broadest 

 part). The anterior end is slightly broader than the posterior. 

 The whole surface is uniformly covered with cilia. There 

 are no ventral hooks or any other sort of spines. Thus it is 

 found that these males possess very nearly the same external 

 characters as those of the males of Hamingia ijimai. So 

 also in their internal anatomy both males of the two species 

 seem to be almost identical. Only points of slight difference 

 can be mentioned; these are : 



(1) In the present species the body-cavity of the tail-region 

 extends a little further posteriorly than it does in Hamingia 

 ijimai. 



(2) The alimentary canal is complete in the pi'esent species, 

 while in H. ijimai it consists of many discontinuous pieces. 



(3) The sperm-reservoir in the present species is a little 

 longer than that of H. ijimai. 



But none of these features seem to be of decisive specific 

 characters. We may naturally expect a close morphological 

 similarity between two such forms as H. ijimai and A. 



