318 A MONOGRAPH OF THE AUSTRALIAN SPONGES, 



I. AULENA VILLOSA AULOPLEGMA, 



WITHOUT PSEUDOSCULA. 



II. AULENA VILLOSA NARDORUS, 



WITH PsEUDOSCULA, 



65. SPECIES. 

 AULENA FLABELLUM, NOVA SPECIES. 

 This species has been obtained only as Auloplegma, without 

 Pseudoscula. 



Shape and Size. 



As indicated by the specific name this species is flat, extended, 

 frondose and fan-shaped with a short peduncle. The sponge does 

 not seem to grow to any large size. The largest specimens measure 

 40 mm. in height, 50 mm. in width ; and the plain fan which they 

 form has a thickness of 4-6 mm. The peduncle is circular cylin- 

 drical 4 mm. high, and in the central thinnest portion 8 mm. thick, 



Color. 



Alive in spirits and dry of nearly the same colour, always dirty 



g'^ey. 



Surface. 



The villi are disposed in a somewhat regular manner, so as to 

 form straight lines, which radiate towards the margin from the top 

 of the peduncle. Otherwise this species represents Aulena villosa 

 very closely in the structure of its surface. 



Structure, 



The internal structure is closely allied to that of the foregoing 

 species, the skeleton indicates however, a tendency to form main 

 radiating fibres in this way, that at certain intervals, portions of 

 the nniform network of threads are slightly thickened (Plate 

 XXXV., fig. 25.) From joint to joint such fibres are thickened, 

 which lie in a radiating line, and so a main fibre is indicated. 



