283 



A vertical sectiou through the living animal shows a yellowisb 

 parencliyrae. The cortex is bright yellow ; its peripheral part dark 

 grey. Only a few luaiii excurrent canals are visible. Ou the sur- 

 face one can see stomions irregularly dispersed. They ave the en- 

 trances of short canals and lacunae, which then coramunicate 

 with irregular chones, which however in certain cases can be 

 distiugiiished. Under the fibrous cortex is a layer of crypts, from 

 which ramifying canals start. Prosodi and aphodi are both narrow, 

 rather long. The aphodi unite into groups and debouch into main 

 canals, which communicate with crypts. The excurrent chones are 

 as irregular as the incurrent ones. 



The skeleton is arranged radially. Bundies of oxeas radiate 

 from a common centre. Towards the periphery plagiotriaenes and 

 anatriaenes appear. These bundies pass through the cortex, but 

 do not project beyond the sponge surface. The cortex is distinctly 

 marked out by the fibrous tissue of the innermost parts. The 

 peripheral, lacunar part is without fibres , but is strengthened by 

 radial protriaenes. The dermal skeleton is formed by a single 

 layer of sanidasters. Both in the cortex and in the parenchyrae 

 there are numerous oxy asters and on some places chiasters. 



Spicules. Oxea. Stout, straight or curved. 



Plagiotriaene and dichotriaene. In some specimens there are more 

 in other less dichotriaenes , but always they seem to be two modifi- 

 cations of one kind. The cladi are always very stout and short. 



Anatriaene. The cladome varying somewhat in shape. 



Oxyaster. Actines generally slender; but sometimes short, conical. 



Chiaster. Actines varying in length, more or less distinctly kuobbed. 



Sanidaster. Very minute, frequent in the dermis. 



Stelletta grubii O. S. 



Syn. 1862 Stelletta boglicii O. S. 

 1864 Stelletta dorsigera O. S. 

 1868 Stelletta anceps O. S. 

 1888 Astrella anceps Soll. 

 1888 Astrella dorsigera Soll. 



