NOTES ON A DEEP-SEA ECHIUKOID. 147 



consist of three main stems on one side, arising widely apart 

 from each other and from the rectum. The single oviduct is 

 of the same shape and position as that of Ac. shiplei. The 

 males have a Nematode-like shape. The whole surface is 

 uniformly ciliated. No ventral hook is present. The 

 spermatic duct is long and wide, ending with a single 

 funnel. 



Zoological Laboratory, 



University of Cambridge ; 

 Ma v. 1910. 



EXPLANATION OF PLATE 10, 



Illustrating Dr. Iwaji Ikeda's "Notes on a Deep-sea Echiu- 

 roid, A c a n t h o h a m i n g i a s h i p 1 e i i^^. g. et n . sp .) , with 

 Remarks on the Species Hamingia ijimai, Ikeda." 



Fig. 1. — Ventral view of the animal ; natural size. 

 Fig. 2. — Yentral view of the proboscis tip ; magnified about five 

 times. 



Fig. 3. — Surface view of the skin in the middle part of the l)ody, to 

 show the aiTangement of the papilla? ; magnified about fifteen times. 



Fig. 4. — A magnified view of a papilla of a larger size. 



Fig. 5. — Transverse, slightly obliquely cut section of the skin, passing 

 through a papilla : seen with oc. 2 and ob. D (Zeiss) ; c, corpuscular 

 ceU in a lacunar space (lac.) ; c. m., circular muscles ; cu., cutis ; ep., epi- 

 dermal epitheliiim ; fb., fibrils in the cutis; p. <jl., papillary gland-cells. 



Fig. 6. — Yentral hooks in the genital groove ; seen with oc. 2 and 

 ob. A (Zeiss). 



Fig. 7. — Ventral hooks of Ac. ijimai; seen with oc. 1 and ob. AA 



(Zeiss). 



Fig. 8.— Rectum near the anus with the roots of the anal glands (on 

 the right-hand side) and the nerve-cord (».) and ventral vessel (r. v.) ; 

 magnified about ten times. 



Fig. 9. — A sketch showing the oviduct {od.) and the blood-vessels in 

 situ; very slightly enlarged; c.i., collateral intestine; d.v., dorsal 

 vessel ;/. ^., fore-gut ; ni.g., mid-gut; m.s., mesentery supporting the 

 ventral vessel ; n. i. v., neuro-intestinal vessel ; p/i., pharynx; v. n., nerve- 

 cord; V.V., ventral vessel. 



