206 SPONGELIA. 



tific Eesnlts of the Voyage o£ H.M.S. ' Challenger,' Zoology, vol. xi. 

 Keratosa, p. 41 (1884). 



Small, incrusting, massive, cake-shaped, or upright lamellar sponges, which 

 attain a thickness of 30 millim. The surface is covered with large conuli, 

 which in large adult specimens attain a height of 6 millim. and are 6-10 millim. 

 apart. In small, young specimens the conuli are only 4 millim. wide. I believe 

 that the ' Challenger ' sponges described by Polejaeff as Spongelia sjpinifera, 

 var. parviconulata, were young specimens of this species. There is generally 

 only one osculum, 10 millim. wide, in a large specimen. In smaller specimens 

 there are generally several oscula 2-3 millim. wide. The colour of the living 

 sponge is greyish violet. Spirit-specimens are generally dirty greyish yellow 

 in colour. The sponge is soft and resilient. 



The skeleton consists of a number of separate dendritically ramified fibres 

 which are not connected with each other by any transverse fibres. These den- 

 dritic fibres consist of an axial column of sand-grains and spicule-fragments, 

 which is surrounded by a stout layer of stratified spongin. The final ramifi- 

 cations of these fibres, which terminate in the conuli — about four conuli are in 

 large specimens supplied with the branches of one fibre — are 0*05 millim. 

 thick. At the base the stems often attain a thickness of 0-8 millim. and 

 more. 



From the conuli twenty-five to thirty stout bands radiate, which ramify and 

 anastomose to form a very conspicuous network of prominent ridges with 

 meshes 1-1*5 millim. wide in the surface. These are traversed by secondary 

 bands which divide the large primary meshes into secondary ones, 0*3 millim. 

 wide. Li each of these eight or ten inhalant pores, 0*04 millim. wide, are 

 situated. The subdermal cavities are larger in this than in the other species, 

 and traversed by irregular membranes and trabeculse. The inhalant trunks are 

 0"25 millim. wide and numerous ; they are only slightly branched themselves, but 

 give off numerous little branchlets which supply the ciliated chambers. The 

 latter are oval, and most of them measure 0-08 millim. in length and 0-055 

 millim. in width. There are, however (at least in the Australian specimens 

 examined by me), a few much larger chambers of similar shape, which are 0-12 

 millim. long and 0-067 mUlim. broad. The exhalant canals extend downwards 

 and open out into irregular lacunae extending at the base of the sponge, from 

 which the oscular tubes arise. 



Geogeaphicai Distkibtjtion. — Adriatic : Lesina, Dalmatian coast {F. E. 

 ScJiulze). 



South coast of Australia : Port Phillip (Lendenfeld). East coast of Australia : 

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



