Sponges from South Australia, 455 



fibre in the sarcode bearing spicules proper totlie species ; the 

 whole traversed plentifully by the canals of tlie excretory 

 systems, which end in the vents mentioned. Spicules of two 

 kinds, viz. skeletal and flesh-spicules : — 1, skeletal, straight 

 or flexuous, fine, smooth, almost cylhidrical, slightly con- 

 stricted at one end, so as to present the appearance of an 

 incipient inflation, abruptly pointed or obtuse at the other, 

 about 65 by |-6000th in. (fig. 7, a) ; 2, flesh-spicule, very 

 peculiar in form, consisting of a thick, cylindrical, C-shaped 

 shaft, about 3-6000ths in. long, spined over the convexity 

 towards each end (fig. 7, J, and fig. 8, a, d) ; spines obtuse, 

 erect, six or more in number, continued backwards from each 

 end for about one third of the length of the shaft, leaving the 

 central third smooth (fig. 8, a) ; ends, when viewed directly, 

 presenting a triangular form simulating those of an equian- 

 chorate (fig. 8, d) . Sand-fibre, which greatly predominates in 

 quantity over the spiculation, and thus affords the chief skeletal 

 support, composed of comparatively large grains of quartz and 

 other foreign microscopic bodies forming a thick fibre about 

 l-90th in. in diameter, that is, about as broad as the skeletal 

 spicule is long (fig. 9, ^ ) . No. 1 scattered through the body 

 generally or surrounded by a minimum of kerasine in fibrous 

 bundles ; no. 2 also scattered through the sarcode generally, 

 most abundant on the surface. Size of specimen about 6 in. 

 high by 4 X 4 in. horizontally. 



Log. Port Western. 



Ohs. Were there nothing but the peculiarly-shaped flesh- 

 spicule, which, viewed in front, looks like an equianchorate, 

 and laterally like a bihamate, to distinguish the species, this 

 would be sufficient ; but with the presence of the thick sand- 

 fibre the combination is unmistakable, especially with the 

 monticular elevations pierced by the circumferential ends of 

 the sand-fibres and the unusual thickness of the skin or cortical 

 layer which the pores have to traverse, so that instead of 

 being holes in a thin film, they consist of so many short 

 canals .in a thick one. 



In general structure and colour like a Halichondria, while 

 the sand-fibre is like that of a Psammonematous sponge ; 

 hence I have named it provisionally Pseudohalichondria 

 clavilobata, not forgetting that it possesses a spiculation which 

 in form hitherto has not been found in any species of Hali' 

 chondrtaj or, indeed, in any other kind of sponge. 



Pseudoesperia eiiigmatica olim Esperia parasitica. 



In 1885 (' Annals,' vol. xv. p. 108, pi. iv. fig. 1, a, h) I 



31* 



