spoNaiiDA. 467 



cymose manner into branches. Branches in part subcylindrical, in 

 part compressed like the stems, of same diameters as stems ; they 

 divide and subdivide and anastomose irregularly, and frequently 

 terminate in short vermiform tips about 10 millim. long by 2 mUlim. 

 thick. Surface of sponge even, smooth. Texture in spirit rather 

 tough, but dough-like, somewhat elastic. Internal structure sub- 

 compact, excretory canals small. Vents small, few, oval, 1 miUim. 

 in greatest diameter, with thin collapsing margins ; near ends of 

 branches. Colour in spirit pale greenish white. 



Main skeleton consisting, beneath surface, of very loose spicular 

 tracts confusedly arranged ; at" the surface they are set regularly at 

 right angles to it, and are about 8 to 10 spicules broad, with in- 

 tervals of -07 to -14 millim. between the tracts. Dermal skeleton 

 formed by the points of the vertical tracts just mentioned, which do 

 not project from the surface, and by a single thin layer of spicules 

 scattered horizontally on the. surface. Sarcode very pale, transparent. 

 Spicules smooth, subspinulate, straight or slightly curved ; head 

 merely a slight enlargement of shaft, only slightly larger than 

 adjacent part ; shaft tapering to sharp point from near base ; size 

 •28 by -0063 miUim. 



Hah. Port Jackson, 0-5 fms. 



A single spirit-specimen, 90 millim. (3^ inches) high, 55 millim. 

 (2i inches) in diameter. This species recalls in colour and consist- 

 ency Suberites carnosus, which, however, differs in its compact form 

 and in the basal protuberance on the head of its spicule. The 

 habit of growth is more that of Suberites antaretieus, Carter 

 (Ann. & Mag. N. H. 1882, ix. p. 350) ; but in that species the 

 colour is dark brown, and the spicule much larger and provided 

 with a large spherical head. It is near H. caruncula, only the spi- 

 cules are of a rather smaller average size, and the head is slightly 

 more pronounced ; but the chief differences are the erect branched 

 growth as opposed to the horizontal, merely mammillated habit of / 

 H. earwneula, and the pale whitish, not brown or yellow, colour. 



97. Hymeniacidon, sp. 



A small incrusting specimen of a duU dark crimson colour, in 

 spirit ; the margins glabrous, the centre of the surface roughened 

 by small conuli about -5 millim. high and -5 to 1 miQim. apart. 

 Primary skeleton-lines compact, about 10 spicules broad. Spicules 

 smooth acuate, tapering gradually to fine points ; size "16 to "22 by 

 ■0042 millim. ' 



Hah. "West Island, Torres Straits, 7 fms. 



SPIEASTRELLA, Schmidt. 



In accordance with the rules of zoological nomenclature, the 

 generic designation Suberites (Nardo) should be retained for those 

 snecies only which are generioally identical with the type of Nardo's 

 ^ 2h2 



