Sponges jrom South Australia. 123 



largest specimen (of which there are three) globular, nearly 

 3 in. in diameter. 



Depth 20 fath. 



Ohs. This specimen is infested with a short oscillatorian 

 parasite in great abundance, wliose filaments vary in length 

 under 25-6000ths in. The species has been j^^ovisionally 

 inserted here for the reasons mentioned in my observations 

 on the " group," p. 45 antea). 



Group 25. S T E L L E T T I N A. 



28. Stelletta haciUifera^ var. rohusta, Carter (^ Annals,' 1883, 

 vol. xi. p. 351). 



Massive, globular, sessile, or attached by one part of its 

 circumference. Consistence hard. Colour when fresh " dull 

 maroon-red," now sulphur-yellow, internalli/. Surface hard, 

 minutely granulated. Vents scattered here and there over 

 the body, chiefly towards the point of attaciiment. Spicules 

 of four forms, viz. : — 1, " the body-spicule," as usual, a large 

 acerate, 245 by l^-6000th in. ; 2, " zone-spicule " or tetrac- 

 tinellid, arms simple, expanded laterally and rather recurved, 

 head ll-6000ths in. broad, shaft 120 by l^-GOOOth in.; 



3, flesh-spicule, bacillar, 12 by l-6000th in., spined all, over; 



4, flesh-spicule, stellate, 2 GOOOths in. in diameter. No 

 " forks " or " anchors " were seen, which may or may not 

 be a constant feature. Flesh-spicules confined to the dermal 

 layer, which is thin and receives the heads of the zone- 

 spicules, together with the outer ends of the body-spicules or 

 large acerates. Structure internally consisting of the body- 

 spicule chiefly, imbedded in sulphur-yellow sarcode, which 

 still retains its brilliancy, traversed largely by the canals of 

 the excretory systems^ especially about the centre. Size of 

 specimen If in. in diameter. 



Depth 19 fath. 



Ohs. If not the same this seems to differ so slightly from 

 Stelletta, hacillifera^ var. rohusta^ Carter (/. c), as not to re- 

 quire a distinct appellation ; but as the latter was described 

 in the dried state, in which the colour of the interior wlien 

 fresh could not be determined, I have thought it desirable to 

 describe Mr. Wilson's specimen also, as the yelloto colour of the 

 interior is so bright and striking. ()f conrse, to become better 

 acquainted with the species it will be advisable to read what 

 1 have published on the subject where the original has been 

 described. 



29. Stelletta ceruginosa. 

 Globular, sessile, that is adhering by one part of the cir- 



9* 



