SPONGES FROM COASTAL BEACHES OF N. S. WALES — WHITELEGGE. 105 



Four examples are referred to this species. The sponge has 

 several points of attachment, and consists of a series of meander- 

 ing lamellje ; the oscula are thickly scattered along the margins 

 of the lamellae, and occasionally on the sides ; their diameter 

 varies from 2 to 3 mm. The whole surface, except the margins, 

 exhibit numerous inhalent pores about 1 mm. in diameter. The 

 main fibres terminate at the surface, giving it a hispid appearance 

 like that of Thorecta tenuis, Hyatt. The texture is, however, 

 much closer, and the surface more even. The main fibres are 

 interruptly cored with sand grains, and are very uneven, especially 

 at the nodes, or rather at the points of origin of the secondaries. 

 The largest example is 170 mm. in length, 100 mm. in height, 

 and 140 ram. in breadth ; the lamellae vary from 15 to 40 mm. 

 in thickness. 



Four specimens from Swansea. 



Thorecta tenuis, Hyatt. 



(Plate xiv., figs. 28 - 28a). 



Spongelia rectilinea, var. tenuis, Hyatt, Mem. Bost. Soc. Nat. 

 Hist., ii., (4), 1877, p. 537, pi. xv., fig. 13. 



Thorecta exemplum, var. prima, Lendenfeld, Aust. Must. Cat., 

 xiii.. Sponges, 1888, p. 143; id., Mon. Horny Sponges, 1889, 

 p. 357, pi. xxiv., fig. 7. 



This species is well represented in the Fisheries and the Museum 

 collections. 



A specimen from Lake lUawarra is the exact counterpart of 

 the example figure by Hyatt in every character except size. It 

 measures 140 mm. in height, 160 mm. across the cup, and the 

 cavity is 145 mm. in depth ; the attachment base is 50 mm. in its 

 lesser and 1 10 mm. in its longer diameter. The wall of the cup is 

 from 15 to 25 mm. in thickness. 



Another example from Botany Bay, with the sand cortex more 

 or less complete, equals Hyatt's specimen in size, the height being 

 223 mm. The peduncle is generally short, very broad, and often 

 exhibits a series of root-like processes around the outer margin. 

 The external surface in the cup-shaped forms is usually ornamented 

 with broad, rounded, longitudinal ridges, which are strongly 

 marked at their origin and gradually fade away towards the 

 upper margin ; the larger ridges have a corresponding depression 

 on the inner side of the cup. In the valleys between the ridges 

 there are numerous inhalent pores about 1 mm. or less in diameter ; 

 on other parts they are indistinct, and when the cortex is intact 

 they are difficult to see without a lens. The inner surface exhibits 

 a great number of oscula from 1 to 2"5 mm. in diameter ; they 

 become smaller as the margin is approached, and cease at about 



