70 



K. MITSUKUKI ; STUDIES OX 



ventral porisomc, the CMlcareous deposit is greater in (quantity. 

 Tlie si)icules are made on essentially the same i)lan as those in 

 the dorsum, i.e., tlicy are rosettes but of a nuich pluni])er 

 appearance (d). The most delicate among them come near 

 to the dorsal rosettes, l)ut are plumper even then. The more 

 plump among them are decidedly broader. They may even 

 become oval or l)iscuit- shaped grains with or without holes [c). 

 They measure 22 — o()a. 



Anus in life a large circular opening with live groui)S of 

 small papillae projecting into it. It no doubt l)ecomes stellate, 

 according to the condition of preservation. 



Tolian vesicle one, long, may be over 5 cm., situated in the 

 left ventral interradius. Stone-canal attached to the mesentery, 

 running forward in a, sinuous course from the circumoral vessel, 

 terminating near the calcareous ring with a slightly enlarged end. Cal- 

 careous ring as figured in a. Cuvier's tubes developed mostly on the 

 left respiratory tree, but some on 

 the right also. The tubes to- 

 gether form a very large mass. 



licmarL's : -Liu-Kiuan name 

 — " Suna-haya." 



Among the species T have 

 examined, //. anjiis, IL marmorcüa 

 and the present species reseml)le 

 one another very closely. I there- 

 fore think that ThKEL's belief of ventmm; J— riump rosette of ventruiii. 



that II marmorata, IL an/as, IL "'-^x^oo). i-intorradiuUa ; ii-Kadiaiia. 

 vUlensls, IL icnuisslma, IL höUlhcrl, IL cleuicns, IL ximilis are 

 probably only young individuals or varieties (jf one and the same 

 species, lias much to recommend it. A somewhat exhaustive 



c^^l 





Textfig. IS. 



Ilolitlhurvi hivitldt'i : a — Calcareons ring; ; h 

 Delicate rosette of dorsum; c — Oval qrniris 



