310 a monograph of the australian sponges, 



Size 

 The vertical diameter varies from 25 — 40 mm. Horizontally 

 the sponge generally measures a little less than in height. 



Color. 

 The color of the live sponge is yellowish-gray, but seems to be 

 subject to variations. In spirits and dry the sponge appeai-s dirty 



Surface. 



The surfaceof the sponge iscovered by densely situated cylindrical 

 and terminally rounded conuli. (Plate XXX., fig. 14, 15, Plate 

 XXXI., fig. 19, 20.) These conuli are about 2 mm. high, and 

 0*8 1 mm. broad ; they are about 1*4 mm. apart from one another 

 and circular on transverse section. The direction in which these 

 conuli proti'ude from the surface varies to a certain extent. They 

 invariably radiate from a common centre ; but this centre may 

 be situated further up or further down as the case may be. In 

 some specimens this centre coincides with the centre of the sponge ; 

 then the conuli stand vertical on the surface. (Plate XXX., 

 fig. 14;, in others again, this centre lies near the base of the sponge, 

 and then the conuli all appear to tend upward. (Plate XXX., 

 fig. 15, Plate XXXI., fi^. 20.) This makes a great difference to 

 the appearance of the sponge, although it is immaterial. It appears 

 that the locality where the sponge grows has something to do with 

 the direction of the conuli, but as the specimens at my disposal are 

 but few in number I cannot assert this. 



These conuli are rather soft and may move with the current of 

 the water. This peculiai-ity makes the sponge appear villous, and 

 from that the s]>ecitic name has been taken. The surface of the 

 conuli is soft. Microscopic investigation shows that there are no 

 foreign bodies, sand, or anything of that kind in the outer skin. 



The surface in the depressions between the conuli is formed of a 

 very fine soft and tender membrane, perforated by large circular 

 pores which lead into the system of vestibule lacunae below. The 

 Pseudoscula. when present are few in number, 1-4, circular and on 

 the upper surface they measure 2-5 mm., in diameter. 



