254 K. MiTsuKum : studies on 



ventral ambulacra the pedicels, especially in the middle part, are 

 more crowded than on the bivium. The interambulacra are free 

 of pedicels and papillae on both dorsal and ventral surfaces. 

 Tentacles ten, the two ventral ones small. Althougli I am unable 

 to make a searching examination on this unique specimen, the 

 tentacles appear to me not to have the usual dendritic shape, but 

 to be formed of a series of fiat plates attached along the sLem, 

 somewhat in the fashion of cephalopod gills. Of the calcareous 

 ring, the radialia are three-pointed anteriorly, while the interradialia 

 are single -pointed (textfig. 51 a). No posterior prolongations on 

 either. There is one large stone -canal. 



The calcareous deposits are abundant. They entirely cover 

 the body like armor. They consist each of a large smooth-edged 



plate with numerous holes 

 in it. Here and there, 

 mixed with these plates, 

 are smaller ones which 

 have a far smaller num- 

 ber of holes (b). These 

 smaller plates are especial- 

 ly heaped up at the base 

 c.«., ..„».„.r"f?o„S;e„,. ...; .-s„.„» and on the sides of pedicels 



perforated plate, x GO. I-Inteiradialia ; H-Eaaklia. ^,y]^ic\^ liavC Cud-plateS. 



In tlie tentacles, there are also supporting rods wiiich are spiny. 



Remarhs : — Tliis species is undoubtedly near C, munita Sluiter 

 and C. hyndmanni Thompson. However, it differs from the former 

 in having calcareous deposits crowded in the pedicels, and from 

 the latter in the shape of the supporting rods in the pedicels. I 

 can not identify this species with any hitherto described, and 

 am therefore obliged to establish a new species for it. 



