7«S Froceedings of the Royal Society of Victoria. 



The flagellated chambers (if one may use the term) are 

 greatly elongated, tubular and copiously branched ; their 

 terminal branches end blindly beneath the dermal mem- 

 biane. I'heir walls are thin and pierced by numerous 

 })rosopyles. There is no central gastral cavity but the 

 chambers open into exhalant canals, devoid of collared cells, 

 which convei'ge towards the oscula. The scattered dermal 

 pores lead into wide, irregular sjjaces between the tubular 

 chambers. 



The skeleton is extremely simple, consisting of small, 

 regular triradiates, irregularly scattered in the walls of the 

 chambers and exhalant canals, and in the dermal membrane. 

 All the spicules are alike, except that some exhibit an 

 incipient apical ray. The rays aie stiaight, conical, fairly 

 sharply pointed ; measuring about ()"1 by 001 mm. 



Localities. — Near Port Phillip Heads (Stations 1 a)id 5, 

 coll. J. B. Wilson) ; Watson's Bay, Port Jackson (coll. T. 

 Whitelegge). 



2. Leucasciis clavatus, n. sj). 



The t3'pe specimen of this species is a sub-globular sponge 

 about 14 mm. in maximum diameter, with a single rather 

 wide osculum. It very closely resembles L. simplex in 

 general appearance, canal system and skeleton, and the only 

 point of distinction of any importance which I have been 

 able to find consists in the presence in L. clavatus of large 

 club-shaped oxea lying at right angles to and with the 

 club-shaped extremity projecting slightl}' beyond the dermal 

 surface. These spicules attain a length of about 07, and a 

 diameter, in the thickest part, of about Ol mm. The outer 

 end of the spicule is usually more or less rounded off and 

 slightly curved, while the inner portion is straight and 

 tapers gradually to a sharp point. The triradiates are like 

 those of L. simplex, and of nearly the same size, perhaps a 

 little larger on an average, 



A second specimen is ii-regularly lobate, and differs from 

 the type in its much denser texture, which is due to the 

 stronger development of the mesoderm. It contains very 

 numerous etnbryos, which fact may be associated with the 

 strong development of the mesoderm. 



Locality.— 'Nenv Port Phillip Heads (coll. J. B. Wilsoii). 



