70 



K. MITSUKCiU ; S'lTDIES ON 



ventral pri'lsomr, ihr calcareous dojiosit is greater in ([uaiitity. 

 The s})ieules are made tni essentially the same plan as those in 

 the dorsum, i.e., they are rosettes l)ut of a, mueli plumper 

 tippearanee (d). The most delicate among them comi' near 

 to the dorsal rosettes, hut are })lumper even then. The more 

 }>lumi> among tliem are decidedly l)roader. Tiny may even 

 hecome oval or hiseuit-shaped graini^ with or without holes (c). 

 They measure 22 — 3(i«. 



Anus ill life a large circular opening with live groups of 

 small papillae [)rojecting into if. It no doubt lii'comes stellate, 

 according to (lie cvnidition of i)reseivation. 



I'olian vesicle one, long, may Ik' over ') cm., situated in the 

 left ventral iuferradius. Stont'-canal attached to the nn'sentery, 

 running forward in a sinuous course fi'om the circumoral vessel, 

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

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

 left respiratory tree, but siimc on 

 the right also. The tubes to- 

 gether form a very large mass. 



J\cinarl>> : -Liu-Kiuan name 

 — " Suna-haya." 



Among the species I have 

 examined, //. arcjus, II. marmorala 



1 ii L • II Textfig. 16. 



and the present species resenu)le 



IfoliAlmria hinlldla : a — CalciireouK ring ; li 



one another very closely. I there- „ ,. , 



" " — i'elicate wselte oi dorsum ; c — Oval grniiis 



fore think that ThKEL's belief of ventmm; -/-riump r.«eltc of ventniiu. 



that //. marmorala, II ai-f/tis, IL "'-'x^od). i-intermai,am ; u-Kmiiniia. 

 vUiensis, 1[. fentiissima, II. koUiheri, II. cleiiieus, II. similis are 

 probably only yt)ung individuals or varieties of one and the same 

 species, has much to recommend it. A somewhat exhaustive 



