204 SIGMATELLA.. — HAASTTA. 



cesses are regulai'ly cylindrical, about 30 millim. long and 15 millim, thick ; 

 they are distally rounded or cut off abruptly — truncate. The surface is smooth. 

 On the summit of each of the digitate processes which crown the upper margin 

 a circular osculum 4 millim. wide is situated. The colour of the living sponge 

 is dull yellowish. Dry specimens are grey. 



The oscular tubes are perfectly straight, cylindrical, and of uniform width 

 throughout ; they extend right down to the base of the sponge, from whence 

 they radiate to the margin, where they terminate in the oscula on the summits 

 of the digitate processes. 



There are no other anatomical peculiarities of a distinctive nature to be 

 recorded in this variety. 



Geographical Distribution. — South coast of Australia : Port Philip Heads, 

 V. (B. Wilson) ; Port Phillip, V. {Lendenfeld). East coast of Australia : Port 

 Jackson, N. S. W. {Lendenfeld). 



Subfamilia SPONGELIN^. 

 Spongelidae without proper spicules in the ground-substance. 



Genus HAASTIA, n. gen. 



Spongelidae the skeleton-fibres of which are sheathed with a 

 dense layer of minute oval siliceous spicules. 



Haastia navicularis, n. sp. 



The sponge consists of a bunch of erect, cylindrical, digitate processes, about 

 15 millim. thick, which grow up from an extensive basal incrusting mass. The 

 whole sponge attains a height of 150 millim. The surface is covered with 

 uniformly distributed conuli, 1 millim. high, which are 1*5-2 millim. apart. 

 The oscula are confined to the summits of the digitate processes. The colour 

 of the living sponge is pinkish grey. In spirit it is light grey. The sponge 

 is soft, resilient, compressible, and pretty elastic. 



The skeleton consists of a very loose network with irregularly square meshes 

 2 millim. wide. Main and connecting-fibres can be distinguished. The main 

 fibres are 0*4 millim. thick, knotty, and completely filled with foreign bodies. 

 The connecting-fibres are simple, unbranched, irregularly curved, and about 

 0*2 millim. thick ; they do not contain so many foreign bodies as the main 

 fibres. A sheath of oval siliceous bodies surrounds the fibres. 



Geographical Distribution. — New Zealand: Port Lyttelton {Haast, 

 Lendenfeld). 



