220 AKT. 7. 1. IJIMA : UEXACÏIMÙLLDIA, IV. 



malia are represented by paratangentially situated slauraetiiis ; 

 more rarely by tauactins. Certain diactins seem also to lend 

 themselves to the formation of hypodermal strands. 



The dermalia (Bl. XL, figs. 3 and 4) are predominantly 

 stauractins, occasionally pentactiiis and tauactins and rarely 

 diactins. The rays are slightly rough all over and have rounded 

 tips, which are occasionally somewhat swollen. The size varies 

 considerably, some of the spicules being in axial length twice or 

 even three times as long as the smallest. Thus, a small dermalia 

 measured had rays of only 90 /^ length and n thickness at base, 

 while a large one may have rays 270 n long and 13 n thick. 

 The largest nearly approaches the size of the smallest hypoder- 

 malia, but the latter seem to be always distinguished from tha 

 former by the fact that the rays are rough at the ends only. 

 Exceptionally thin-rayed and smooth oxystauractins, found here 

 and there in the dermal layer, I take to be dermalia that are 

 still in an incomplete state of development. The sei)arate dermalia 

 are irregidarly disposed as regards the mutual orientation of their 

 paratangentials. 



The gaüralia (PI. XL, fig. 5) are pentactins and stauractins, 

 the former being present in somewhat greater relative abundance. 

 Rarely are they tauactins or diactins. The rays are quite like 

 those of the dermalia but are generally smaller. Length of rays, 

 55-100 /A Average thickness at base, 62 //. In the pentactins 

 the unpaired ray is directed distad ; sometimes the proximal ray 

 is represented by a boss. The gastralia are nowhere numerously 

 present. 



