50 



I. IJIMA. 



Rh. Dowlingi. Of these three species, only one, i. e. mollis, is retainable 

 in the present genus as defined above, while I will now add to it two 



new species. 



2. Rhahdocalyptus mollis, F. E. Sch. 



Cup-like or vase-like, laterally compressed, contracted below, bear- 

 ing one or more tube-like secondary persons. The body may attain a 

 height of more than one foot. 



Parenchymal diactins short, not exceeding '20 mm. in length. Disc- 

 octasters especially abundant in the subdermal region ; ray-length 

 (measured from centre) 65-88,« ; terminals 5-9 to a principal, rarely as 

 few as 2, straight or only slightly bent outwards ; terminal disc 7-8 

 toothed or simply pin-head like. 



Oxyhexasters 51-80,« in radius. Two varieties are distinguishable. 

 Those situated in deeper parts have usually two-forked rays, the princi- 

 pals being very short and often obsolete ; terminals smooth or minutely 

 rough, but always with more or less well developed basal barbs. Fre- 

 quently there is only one terminal to a principal, and hexactin-shaped 

 oxyhexasters are of common occurrence. Oxyhexasters found in the 

 subdermal region have longer principals and bear 2-4 usually 3 rough 

 terminals which are thinner and supplied with less prominent basal 

 barbs. Oxyhexasters with spirally twisted rays are not of constant 

 occurrence. 



Microdiscohexasters of usual shape occur in variable numbers, es- 

 pecially in or near the dermal membrane. 



Autodermalia are predominatingly rough diactins. Hypodermalia 

 consist of pentactins, pronged in fully developed state, and of smooth 

 diactins. The former have either paratropal or regularly cruciate heads, 

 and in places protected from external influence, may stand out isolated 

 as prostalia. Such a pentactin has paratangential rays not exceeding 

 5 mm. and a radial ray of not over 10 mm. in length. 



Autogastralia are rough hexactins with bluntly conical ends, form- 



