52 



I. MIMA. 



Locality : Salami Sea, from depths between 274 and $18 fathoms. 

 4. Rliabdocalj/ptus victor, n. sp. 



Vase-like ; laterally compressed especially at basal part, which is 

 usually bent ; sometimes with one or two secondary persons on the 

 greater curvature of the basal region. Oscular edge simple or with an 

 interrupted fringe of thin diactin prostals. The body may attain a large 

 size, almost 3 feet high. 



Parenchymalia may contain stout bow-shaped diactins, 28 mm. long 

 and 0.4 mm. bread at middle. Discoctasters 90-120/;. in radius ; termi- 

 nals 4-8 in a tuft, straight or slightly bent outwards ; terminal discs 

 pin-head like. 



Oxyhexasters 90-140« in radius. Principals exceedingly short or 

 obsolete, usually two-forked. Terminals rough, which character changes 

 towards base into small, inwardly directed prickles. Oxyhexasters with 

 two terminals to every principal occur less frequently than those in 

 which one or more principals bear only one terminal. Hexactin-shaped 

 oxyhexasters are of frequent occurrence. 



Microdiscohexasters of usual shape and size are of very isolated 

 occurrence. 



Autodermalia consist predominatingly of rough stauractins. Hypo- 

 derrnalia as in foregoing species, but somewhat smaller (paratangential 

 rays 5-7mm. long). Unlike that species, the protruded hypodermal 

 pentactins seem to be readily thrown off, leaving at every hypoclermal 

 centre a little bunch of the external ends of comital spicules, that accom- 

 panied the lost shafts, projected beyond the otherwise smooth surface. 

 In this respect, the present species agrees with Rh. mollis. 



Autogastralia as in Rli. mollis. 



Locality : Sagami Sea, in depths <of over 274 fathoms. Next to 

 Acantliascus cactus, the present species is apparently the most abund- 

 ant octasterophorous Hexactinellid in the locality just mentioned. 



