STAUROCALYPTUS GLABER. 217 



parts. Very frequently they are seen shifted out to a point 

 midway towards, or right on the tip of, the free proximal rays 

 of gastral hexactins (fig. 11). 



The discoctaslers (PL XV., fig. 9) are common in the deeper 

 parts of the wall, probably never occurring in the subdermal 

 space. They may attain a size larger than is known to me from 

 any other Acanthascinje. Diameter, generally 500-660 /^, but 

 sometimes reaching down to 300 /^- or even less. In the very 

 young specimen of only 6 mm. height, the discotasters, of which 

 only two or three in all were found, measured 240-352 /^. 



The central node is of a plain appearance. The secondary 

 principal gently thickens outwards, forms about one-third of the 

 entire ray-length and splits at the outer end into five or six 

 slightly rough, but sometimes nearly smooth, straight and slightly 

 divergent terminals, which together give rise to a tuft of an 

 elongate conical shape. The terminal disc is without marginal 

 teeth, being simply like a 2:)inhead in shape. 



llicrodiscohexaslcrs (PI. XV., fig. 8) of spherical shape and 

 15-22 fi diameter occur extremely rarely in the older specimens, 

 but are not uncommon in the younger. They are found on or 

 near to both the dermal and gastral surfaces. About ten termi- 

 nals of extreme fineness, each having a minute terminal swelling, 

 occur to the flat or externally convex disc at the outer end of 

 each moderately long principal. 



Finally — the basidictyonal plate (PI. XV., fig. 12) is of quite 

 a similar appearance as in other species of the subfamily. In the 

 larger specimens it is of a considerable thickness and consists of 

 both directly and synapticularly connected, thick-rayed and mi- 



