SPONGES FROM COASTAL BEACHES OF N. 8. WALES — WHITELEGGK. 83 



they are about 1 ram. in diameter. The specimen is perforated 

 by a small Isopoda, and it is impossible to distinguish the oscula 

 from the holes occupied by the crustacean. Surface even, reticu- 

 lation very fine and regularly porous ; the pores vary from O'l to 

 0-2 mm. in diameter. Texture compact, tough, and highly elastic. 

 Colour when alive, bright red ; when dry, dark stone, with a tint 

 of red in the deeper parts. 



Skeleton closely reticulate, with oval or oblong mesh, from 0-3 

 to O'O mm. in the longer diameter, and about 0-1 to O'lo mm. in 

 the shorter. Primary fibres from O'l to 15 mm. in diameter, 

 with much yellow spongin, and a few ill-arranged stylote spicules, 

 rarely with more than six in a row, frequently four or less. 

 Secondary connecting and dermal fibres, usually bi- or unispiculous, 

 diameter from 0'025 to 0-05. The echinating styli are abundant, 

 and irregularly scattered on the fibres, but rarely more than their 

 length apart. 



Megascleres — (a) Stout, slightly curved, subfusiform, smooth 

 styli ; base rounded, with or without a contraction about one 

 diameter from the end ; shaft gradually tapering from the middle 

 to the acute apex. Size — O'l 4 by O'Ol mm. (b) Slender straight 

 smooth styli, a little inflated at the base, and rather suddenly 

 acute at the apex. Size — O'll by O'OO-l mm. (c) Spined styli, 

 gradually tapering from a rounded or slightly swollen base to an 

 acute apex; spines numerous, but small. Size — 0"7 by 0-0075 mm. 



Microscleres— (a) Small isochela^. Size — 008 to 001 mm. 

 (6) Short stoutish toxa, with a central bend about 0-03 mm. in 

 depth ; the shaft is gracefully curved on each side of the centre, 

 and the ends are smooth and sharp pointed. Size — O'OS to O'l mm. 

 (c) Rather slender toxa, with a slight median band, the ends are 

 smooth and acute. Size — 0*13 to 0*13 mm. 



One specimen from Lake Illawarra. 



I collected two examples of this species at Wollongong some 

 years ago. 



Clathria dura, sp. 'not: 



(Plate xi., fig. 11). 



Sponge rather variable in habit, consisting of a series of com- 

 pressed or cylindrical branches which are often united at various 

 points, especially near the base. The largest example is flabellately 

 expanded; it is about 150 mm. in height, 230 mm. in width, and 

 in the thickest part 30 mm.; individual branches are rarely more 

 than 5 mm. in their lesser diameter. The branches arise from a 

 short stout peduncle ; they are compressed, subradiate, and dis- 

 posed in one plane, and more or less connected along their lateral 

 margins ; in some portions the frond is continuous, and in others 

 clathrate. The main branches retain their individuality, and can 

 generally be traced to their origin ; the terminal branches are 



