28 AET. 1.— I. IJIMA : HEXACÏINELLIDA, 111. 



codonliexaster, the aspidoplumicome, or the drepanocome, while 

 the graphiocome, alone hy itself or together ^Yith the floricome, 

 has either been lost or has never come into develoj^meiit. Placo- 

 som.a paradictijiuii, as being in possession of codoiihexasters and 

 wanting in both Horicomes and graphioconies, seems to have its 

 position somewhere in the latter end of the Corbitelliue series, 

 though it is ditHcult to indicate to which of the genera it is 

 inost nearly related. 



The division of the Corbitellime somewhat in the manner 

 hinted at al)Ove may become possible and even necessary in the 

 future ; for a far wider knowledge than we at present possess is 

 to be taken in prospect, when we remember that most of the 

 genera are now known only in solitary species and that too, in 

 so many cases, in a single specimen. 



