242 Proceedings of the Royal Society of Victoria. 



R.N. 480 (x, 20 f ; " vinaceous-cinnamon "); 516 (s. 8, 9 f; 

 "wood brown"); 681 ("sponge-brown"); 819 (s. 1); 944 (x A). 



B.M. sp. 61 (wrongly labelled " Axinella so/ida." Reg. 86- 

 12-15-59). 



Sigmaxinella ciocalyptoides, n. sp. 



Massive, sessile, rising above into short digitiform projections ; 

 the whole apparently formed by the incomplete fusion of 

 numerous vertical processes enclosed below in a common dermal 

 membrane. Surface acutely conulose, grooved vertically ; with 

 very distinct, minutely reticulate dermal membrane supported on 

 fibrous pillars over large subdermal cavities. Vents sometimes 

 large, in depressions of the surface. Texture somewhat cavernous 

 but firm and resilient. Colour in spirit pale greyish-yellow. 



Skeleton, composed of stout ascending columns of irregularly 

 and rather loosely arranged spicules, from which stout plumose 

 spicular fibres radiate outwards to the surface, where they 

 end in small conuli from which the ends of the terminal 

 spicules project somewhat. There is a good deal of spongin in 

 some of the fibres but its development appears to be very 

 irregular. Transverse sections of the vertical processes are 

 extremely characteristic, showing the central mass of spicules 

 occupying about a quarter of the diameter of the section, and the 

 stout radiating fibres coming off from it at wide intervals like the 

 spokes of a wheel and with the large subdermal cavities between 

 their outer ends. There is no dermal skeleton. 



Megascleres, ranging from stylote to oxeote, but chiefly styli ; 

 slightly curved ; variable in size, up to about 0-5 by 0-018 mm. 

 but seldom so stout. 



Microsderes ; (a) signiata, small and slender but extremely 

 numerous, simple and contort, about 0*0166 mm. from bend to 

 bend ; (b) trichodragmata, usually small bundles of short, slender 

 rhaphides about 0'03 mm. long ; often in dense agglomerations. 



The specific name was suggested by a certain resemblance to 

 the genus Ciocalypta, from which the present species differs, 

 however, in the absence of dermal skeleton and the presence of 

 microscleres. 



R.N. 338 (18 f; "Projections yellow-buff, the tympanised 

 interstices grey"); 442 (s. 9, 17 f; " cinnamon, the projections 

 deep chrome"): 882 (s. 9); 1092 (x A). 



