98 RECORDS OF THE AUSTRALIAN MUSEUM. 



they consist of a single series ; their diameter is usually about 

 4 mm. The surface is fairly even and marked by a raised reticu- 

 lation, consisting of ridges, surmounted by rather broad conuli 

 about 5 mm. high, which tend to become seriate and follow the 

 course of the oscula. The inhalent pores are scattered in abund- 

 ance between the conulose ridges ; they are funnel shaped, rather 

 deep seated, and measure from 1 to 3 mm. in diameter ; the 

 conuli are on an average about 2*5 mm. apart. 



The dried skeleton is soft and very elastic ; when wet it is tough, 

 elastic, and apparently very durable. Colour, light yellowish- 

 brown. The main fibres are entirely free from foreign bodies, 

 such as sand grains and spicule fragments ; they are not readily 

 distinguishable from the stouter secondaries : here and there in 

 the central region they are trellis-like in their arrangement ; 

 usually they are 008 mm. in diameter, and 0'2 mm. apart. The 

 secondary connecting fibres are generally curved, the stouter 

 measure 006 in diameter, and the slender kind are about 0'03 

 mm. or less ; the latter occur near the surface and in the less 

 dense parts of the sponge. The skeleton mesh is generally 

 angular or polygonal, about 0'15 mm. in diameter ; the angles or 

 corners are sharply defined, and exhibit little or no thickening at 

 the juncture of the fibres. The above description is based on two 

 examples from Lake Illawarra. A third specimen from Tuggerah 

 Beach differs in shape, is much coarser in appearance, and the 

 texture is more open. The example is only a fragment of a very 

 large sponge ; it measures 200 mm. in height, 250 mm. in length, 

 and about 120 mm. across the broad, flat, upper border, which 

 exhibits fourteen oscula in a tran verse row. The external surface 

 and the fibres do not differ from those described above. This 

 sponge is by far the best occurring on the coast, and is equal, if 

 not superior, to many of the commercial sponges procurable in 

 Sydney. 



EusPONGiA OFFICINALIS, var. SPiNOSA, Lendenfeld. 



JEuspongia officinalis, var. spinosa, Lendenfeld, Mon. Horny 

 Sponges, 1888, p. 273, pi. xxii., fig. 14. 

 A single example of this form was obtained at Ooogee Bay. 

 The specimen is incrusting, and measures 130 mm. in length and 

 90 mm. in breadth ; on one side it is 50 mm, in height, and on 

 the other from 5 to 15 mm. The upper surface exhibits numerous 

 pit-like depressions from 10 to 20 mm. in diameter, and a series 

 of irregular ridges, surmounted by numerous oscula, from 2 to 3 

 mm. wide ; frequently the outer margins of the oscula are incom- 

 plete on one side; this marks the termination of a groove which 

 is often branched at its origin. Occasionally the oscula are 

 surrounded by shallow branched grooves. The surface is minutely 

 villose and extremely harsh to the touch ; this harshness is due 

 to the number of spicules in the slender terminal fibres forming 



