Sponges from South Australia. 41 



16. Hypograntia hirsuta. 



Individualized ; solitary or social. Sacciform, cylindrical, 

 elongate, diminishing towards the free end, which is provided 

 with a long peristome, also towards the fixed one, which is 

 contracted to the point of attachment; covered witli a hairy 

 coat of long spicules, which together with the peristome when 

 dry gives the whole a glistening silky appearance. Colour 

 light grey. Surface overspread with tufts of acerate spicules 

 in the midst of circular cribriform areas, which are more or less 

 arched outwardly. Pores identical with the holes of the cribri- 

 form structure, which are comparatively large. Vent single, 

 terminal, leading toacloacal cavity corresponding in shape with 

 the specimen, a little wider in the centre than the wall, which 

 is comparatively thick ; abundantly echinated with the fourth 

 arm of the quadriradiate ,• holes of the cloaca large, irregular 

 in size and distance apart, being more or less separated by 

 the interspaces which the varying breadth of the superficies 

 of the cavity presents ; showing within the margin, which is 

 profusely echinated, segments of one or more circular sphinc- 

 tered openings which belong to the structure of the wall. 

 Structure of the v.-all consisting of subradial chambers, i. e. 

 only partly radial, arising from the radial form being more or 

 less diverted from parallelism by large holes of intercommuni- 

 cation, besides the usual pores, especially in the outer and 

 inner sides of the wall, where, in the former, they simulate 

 the " subdermal cavities," and in the latter " subcloacal " ones 

 also ; opening in more or less plurality just inside the holes 

 of the cloaca, as above stated ; skeletally composed of small 

 radiates, i. e. " articulated." Spicules of three kinds, viz. 

 acerate, triradiate, and quadriradiate : — 1, acerates of two 

 forms, viz. one thin, smooth, straight, long, silky about the 

 mouth, and the other thicker, curved, and disposed in tutts 

 about the body ; 2, triradiates varying from regular to 

 irregular or sagittal ; 3, quadriradiates, the same, of which 

 the fourth arm may average 20 by 2-6000ths. No. 1 con- 

 fined to the peristome and tufts of the surface respectively, 

 where the latter in combination forms a cone over the outer 

 part of its chamber ; no. 2, chiefly confined to the wall- 

 structure and the surface respectively, where, in the latter, 

 their rays support the cribriform sarcode, arching over the 

 ends of the chambers which are not occupied by the " tufts j" 

 and no. 3 to the cloaca, where the fourth arm thickly echi- 

 nates the surface and margins of the holes of this cavity, as 

 before noticed. Size of largest specimen (for there are several) 

 about 9-12ths in. long, exclusive of the peristome, and 5-12ths 



