STAUKOCALYPTÜS IIETERACTINÜS. 219 



the parenchyma. Close over this is an ill-defined hypodermal 

 network with irregular meshes of various sizes. The dermal layer 

 is only partially preserved, and is very indistinct. The incurrent 

 canalar apertures are represented by small gai)s between the 

 parenchymal strands and quite occasionally by pit-like but «hallow 

 depressions. 



The gastral surface exhibits a nnmljer of freely open ex- 

 current apertures, which may reach up to | mm. in diameter. 

 Some of the excurrent canals are pit-like but never deep in 

 relation to the thinness of the sponge-wall. 



Altogether, the appearance of the wall is much like that of 

 the oscular region of a larger Acanthascine species. 



Spiculation. 



The parenchymalia include an abundance of comparatively 

 strong princijnilia of elongate spindle-shaped or bow-shaped oxy- 

 diactins, which may attain a length of 12 mm. and a breadth of 

 220 fJ- at the middle. In them the ends are smooth. The smaller 

 parenchymalia present no features worthy of special mention. 



The hypodermalia (PI. XL, fig. 2) are moderately large and 

 sti-ong pentactins, occurring commonly but in irregular distribu- 

 tion. The paratangentials, which are regularly cruciate and never 

 paratropal, usnally measure under I mm. in length l)ut are some- 

 times longer. The unpaired proximal ray is always much longer 

 than the paratangentials. The rays may be 30 /^ thick at base. 

 The surface near the conically pointed tip is either quite smooth 

 or sparsely beset with microtubercles. Occasionally the hypoder- 



