198 SIGMATELLA. 



base, and taper from thence gradually towards the upper end. On the summit 

 a circular vent, 7 millim. wide, is situated terminally. The tubes attain in their 

 lower portion a maximum thickness of 40 millim., but rarely exceed 15 millim. 

 in width at the upper end. The colour of the living sponge is dull orange, 

 spirit-specimens are dark grey. In the structure of the surface and the general 

 anatomy this variety does not show any distinctive features. 



Carter states that his Dysidea tubulosa may be identical with Terpios jania, 

 Duchassaing and Michelotti. According to Carter (loc. cit.), our sponge lives 

 symbiotically with a Coralline, Jania. No Janice were observed by me in the 

 Australian specimens. 



Marshall {loc. cit.) has given a detailed description of this sponge. Although 

 this does not tally very well with the observations made by me, I am inclined 

 to consider his sponge identical with mine, and that the discrepancy is to 

 a great extent due to the bad state of preservation of Marshall's specimens. 



Geogkaphical Disteibution. — Coast of North America : Nassau (C. Warren). 

 South coast of Australia : Bass Straits {Marshall). East coast of Australia : 

 Port Jackson, N. S. W. (Lendenfeld). 



Sigmatella australis, var. flabellum, nov. 



Large, erect, flabelliform sponges, which attain a height of 200 millim., a 

 breadth of 140 millim., and a maximum thickness of 40 millim. The free 

 margin is rounded, undulating, or divided by incisions into short and stout 

 digitate marginal lobes. The lamellse are composed of a number of radiating 

 tubes, 8 millim. wide, which lie in one plane and terminate with vents 6-8 

 mUlim, wide, situated on the margin of the lamella. The walls of these tubes 

 are fused throughout their entire length, except in those specimens the margins 

 of which are serrated, in which the distal portions of the tubes remain isolated. 

 The colour of the living sponge is pinkish grey ; dry and spirit-specimens are 

 grey. In the structure of the surface and the general anatomy this variety 

 does not show any distinctive features. 



G-EOGBAPHiCAL DiSTKiBUTiON. — South coast of Australia : Port Phillip, V. 

 {Lendenfeld). East coast of Australia : Port Jackson, N. S. W. (Lendenfeld). 



Sigmatella macropsamma, n. sp. 



Flabelliform sponges with radial longitudinal ridges on the surface, attaining 

 a height of 80 millim., a breadth of 70 millim., and a thickness of 17 millim. 

 The ridges are 5-15 milHm. thick at the base, and have a sharp free margin. 



