Sponges frojii South Australia. 45 



Obs. As in the two foregoing species so here, there are 

 subdermal and subcloacal dlLatations of the wall-structure into 

 which the chambers of the latter open in more or less plurality. 



19. Hypograntia intusarticulata. 



Agglomerated. Specimen consisting of one large individual 

 with several small ones growing out about the base, all with- 

 out peristomes, the former cylindrical, truncate. Colour 

 whitish yellow. Surface uniformly even, composed of cribri- 

 form sarcode densely charged with mortar-spicules and small 

 radiates, so as to completely exclude the sarcode itself, which 

 is thus faced by a minute hispid reticulation. Pores, that is 

 the interstices of the reticulation, large, varying in size under 

 1 -360th in. in diameter. Vent terminal, circular, without 

 peristome, leading into a narrow cylindrical cavity, which, 

 after a short distance, becomes wider and irregular in form as 

 it extends into the smaller individuals ; holes of the cloaca 

 subcircular, very irregular both in size and distance apart, 

 corresponding with the width of the splcular or skeletal frame- 

 work of the cavity ; presenting within their margins respec- 

 tively from one to four openings in connexion with the cham- 

 bers of the walls. Structure of the wall like that of Grantia 

 hirsuta &c., viz. consisting of subradial chambers intercom- 

 municating with each other by large holes as well as the 

 usual pores; partly "articulate" and partly "inarticulate" 

 in the composition of their skeleton, that is the small radiates 

 occupying the inner third and the larger ones, through their 

 long shafts, the outer two thirds of the wall. Spicules of 

 three kinds, viz. acerate, triradiate, and quadriradiate : — 1, 

 acerates, minute, sinuous, thicker towards one end than the 

 other, viz. that which is lance-pointed, about 16 by|-6000th in. 

 in short the " mortar-spicule ;" 2, triradiates, regular and irre- 

 gular or sagittal, of two sizes, viz. one small and the other 

 large, with long shafts averaging 60 by 3-6000ths in., and 

 arms about half this length ; 3, quadriradiates scanty. No. 1 

 is confined to the surface, where, together with small radiates 

 it acts as the mortar-spicules of the dermal reticulation ; no. 2 

 viz. the triradiates, in their smaller size, occupy the " articu- 

 lated " portion of the parenchymal chambers, and the laro-e 

 ones the " inarticulated " part, where their heads are fixed in 

 the cortex and their long shafts traverse the outer two thirds 

 of the wall perpendicularly to the surface ; no. 3, the quadri- 

 radiates, are chiefly confined to the surface of the cloaca, where 

 the fourth arm, which is large, projects into the interior with 

 its curve towards the mouth of this cavity. Size of specimen, 



