Sponges from South Australia. 355 



Group 2. Plumohalichondrina. 



8. PlumoJialicJiondria mammillata. 



Massive, sessile, with mammilliform erect lobes. Consis- 

 tence soft, resilient when wet, hard when dry. Colour, when 

 fresh, " Venetian red," the same now inside, but paling to- 

 wards the dermis. Surface even, uniformly but largely granu- 

 lated ; dermis reticulated over the granulations or elevated 

 parts. Vents large, scattered irregularly over the mass, none 

 at the ends of the mammilliform lobes. Spicules of four 

 forms, viz. : — 1, skeletal, acuate, curved, spined generally, 

 about 35 by l-6000th ; 2, the " tibiella," acerate, almost 

 straight, slightly fusiform and abruptly pointed, about 44 by 

 |- 6000th ; 3, echinating, smaller, acuate, spined all over, 12- 

 GOOOths long ; 4, flesh-spicule, equianchorate, angulate, 4^- 

 GOOOths long. The tibiella is chiefly confined to the axis of 

 the fibre. Nos. 1 and 3 echinating, and no. 4 confined to the 

 sarcode. Structure open resilient, soft generally, no axial 

 condensation. Size of specimen 5 in. high, 6 x 3 in. horizon- 

 tally. 



Depth 3 fath. 



Ohs. Very like the British species, viz. Plumolialichondria 

 phimosa^= Hymeniacidon plumosa^ Bk. (Mon. Brit. Spong. 

 vol. ii. p. 195), and Microciona plumosa, Bk. {ib. vol. iii. 

 pi. xxiv. fig. 7, &c.), but different from the Cape species, 

 wherein the large spinous acuate is mixed up with the tibiella 

 in the axis of the fibre. The Cape species, which might be 

 termed '^P. capensiSy^ is the finest of all that I have seen, and 

 as yet has been undescribed, although it appears to be as 

 abundant as it is remarkably fine. There are many 

 specimens of it in the British Museum from Port Elizabeth, 

 especially those bearing my running no. 74, registered 

 71. 5. 12. 1, &c. 



Group 4. ECHINOCLATHRINA. 

 9. EcMnoclathria tenuis. 



Stipitate, compressed, very thin and leaf-like, lobed all on 

 one side of the stem^ like a one-sided lobed leaf; lobes irregu- 

 larly denticulated on the margin. Consistence firm. Colour, 

 when fresh, " Venetian red," now brown. Surface minutely 

 and uniformly granulated. Spicules of three forms, viz. : — 1, 

 skeletal, subpinlike, fusiform, curved, smooth, 45 by H- 

 6000th, chiefly confined to the fibre ; 2, subskeletal, also sub- 

 pinlike, very tine, thin, and long, 20 by |-6000th, tending 



