268 ART. 7. 1. IJIMA : HEXACTIXELLIDA, IV. 



The microdiscohexasters (PI. XX., fig. 4) are of the familiar 

 appearance. Diameter, 22-27 /A F. E. Schulze found these 

 spicules in especial abundance in the proximity of the dermal 

 membrane. In the preparations that he sent to me I find them 

 quite common in the endosome i.s well as in the subgastral region, 

 once counting as many as a dozen in the same visual field of the 

 microscope. Far less commonly and even quite sparsely were 

 they represented in several specimens in which I have specially 

 looked for them. In these they were to be met with only now 

 and then, both subdermally and subgastrally. 



RHABDOCALYPTUS UNGUICULATUS nov. sp. 



PI. XXI. 



The species here described as new under the above name is 

 unquestionably a very near relative of R. mollis F. E. Sch. and 

 of R. mirabilis. From both these species it can scarcely be said 

 to differ so far as the categorical forms of the spicular elements 

 are concerned ; but in the details of characters I find, common 

 to all the individuals referred to it, certain constant peculiarities 

 which, I think, may be considered to be of specific value. 



I have had at my disposal for examination no less than 

 eight specimens, all of which I place under the present species. 

 The known locality is Okinose, both Inside and Outside ; depth, 

 about 500 m. 



Three of the said specimens are small, young individuals, 

 quite similar in external appearance to the young of R. victor 



