190 ART. 7. — I. IJIMA : HEXACTINELLIDA, IV. 



sufficiently for themselves, so that comments upon them may here 

 be dispensed with. 



Microdiscohexaders (Fl. XIII., fig. 8) of spherical shape and 

 19-20 /^- diameter are not uncommon in or near the endosomal 

 layer. They were occasionally observed in the ectosome also. 

 From a spherical node arise comparatively thick principals, which 

 in length are about I the radius of the rosette and each of which 

 carries at the outer end a small disc, usually provided with a 

 central tubercular prominence on the external side. The terminals 

 are exceeding fine and difficult to count, but probably not more 

 than 10 to each principal. 



Finally, the basidictyonal plate, found preserved in the second 

 specimen, is rather thick and consists of an irregular reticulum 

 of beams of variable thickness (up to 30 /^), inclosing mesh-like 

 spaces up to 100 n in widtli. The beams are beset with small 

 prickles as w^ell as with larger conical protuberances. Here and 

 there can be observed hexradiate axial crosses in the nodal 

 points. Also some rough and thick-rayed hexactins are seen in 

 the first process of being amalgamated with the basidictyonal 

 beams. PL XY., fig. 12, taken from S. glaher, equally well 

 illustrates the condition of the basidictyonalia in the present 

 species. 



The chief })oints in the spiculation of the present species, 

 requiring special attention in relation to such other species as 

 are most likely to be confounded with it, seem to be : the great 

 length and coarseness of the principal parenchymalia ; the large 

 size of prostal pentactins, in which the paratangentials are in 



