58 [. MIMA. 



Microdiscohexasters occur not uncommonly in the dermal, less fre- 

 quently in the gastral, membrane. 



Autoderinalia are almost exclusively stauraetins with rough or 

 prickly surface, the prickles on the external side being unusually well- 

 developed. 



Hypodermalia consist of filamentous diactins and of moderately 

 sized pentactins with cruciate or paratropal heads. Parataugential rays 

 of the latter smooth but with rough ends. These are, I think, never 

 protruded beyond the dermal surface. 



Autogastralia consist of comparatively large prickly hexactins, of 

 whose rays the free proximal ray is the longest (450-500//.). They form 

 a continuous lattice-work with quadrate meshes. 



9. Stcmrocalyptus pleorliapliides, n. sp. 



Thick-walled sac of about the shape and size of a small pear. Oscu- 

 lar edge sharp and simple. The surface shows a number of low hillock- 

 like elevations from the apex of which long diactin prostalia stand out 

 in loose bunches. The body is moreover covered by a veil of pentactin 

 prostalia. Two specimens from Sagami Sea. 



Principal parenchymalia, straight or bow-like ; not over 8 mm. in 

 length. 



Discoctasters with rays 70-98// long ; each principal with 2-4, 

 usually 3, diverging terminals, which are straight or slightly bent out- 

 wards. Discs minute, pin-head like. 



Oxyhexasters with radins of 57// in average. Principals extremely 

 short ; each with two, seldom more, rough-surfaced terminals. Fre- 

 quently one or more principals in an oxyhexaster are uniterminal, al- 

 though hexactin-shaped forms seem to occur but very rarely. 



Microdiscohexasters present in sparing numbers. 



Autodermalia are predominatingly rough diactins. Hypodermalia 

 consist of a few diactins and of numerous pentactins, whose heads are 

 either regularly cruciate or paratropal. Paratangential rays 5 mm. or 



