74 RECORDS OF THE AUSTRALIAN MUSEUM. 



cross each other at the points. The fibres contain very little 

 spongin. The axial string of spicules in the primaries occupies the 

 whole of the fibre, whilst the spicules in the secondaries and 

 dermis are invested with a sheath of spongin about twice the 

 diameter of the spicule. The spicules are stout slightly curved 

 oxea, tapering rather suddenly to acute points at about two or 

 three diameters from their extremities. Size — 0.11 by 001 mm. 

 A few slender forms occur in the ground substance. 



In habit and appearance this species is like a Chalina, yet 

 the small amount of spongin present and the stout spicules are 

 not in strict conformity with the generic definition. 



Three examples, obtained at Tuggerah Beach. 



Chalina ligulata, sp. nov. 



(Plate X., fig. 6). 



Sponge usually with an attachment expansion — a short, thick 

 angular or compressed peduncle, from which a tangled mass of 

 branches arises ; they are mostly disposed in a single plane, and 

 are dichotomously divided. The branches at their origin are 

 short, compressed, or angular, and frequently coalesce; the middle 

 and distal branches are flat, thin, strap-shaped and of nearly equal 

 width throughout their length, with evenly rounded apices ; they 

 vary from 5 to 20 mm. in breadth, 1 to 3 mm. in thickness, and 

 from 10 to 150 mm. in length. Texture of the basal portion of 

 the branches dense, hard, and incompressible ; upper parts of the 

 sponge tough, flexible, and elastic. Colour in the dried state 

 sandy yellow. Surface even, smooth, with a thin dermal incrusta- 

 tion, supported by a very fine meshed reticulation. There are 

 numerous pores about O'l mm. in diameter, and abundant oscula 

 scattered over the surface and along the margins of the branches; 

 their diameter varies from 0'8 to 1 mm. 



Skeleton consisting of a fine rectangular network. The main 

 fibres are from 0'15 to 0-25 apart, 0-08 in diameter, and are cored 

 with an axial thread of rather irregularly disposed oxea, usually 

 about three or four spicules wide. Tiie primaries bend outwards 

 from the centre towards the surface ; they are pretty evenly con- 

 nected by secondaries, al)Out 04 in diameter, forming square or 

 oblong meshes from O'l to 2 mm. in width. The axial series 

 of spicules in the tiner fibres are few, disconnected, and frequently 

 absent, and rarely form more than a single row in the stouter 

 ones. The spicules are straight or but little curved oxea ; they 

 ai'e cylindrical to within three or four diameters of the acutely 

 pointed extremities. Size — 007 by 0-003 to 0'004 mm. 



Seven examples are in the collection from Tuggerah Beach. 

 Several specimens were obtained by the writer at Newcastle in 



1889. 



