214 RECOBDS OF THE AUSTRALIAN MtTSEUM. 



condition. I have never observed any large sand grains in the 

 fibres near the growing apex; and, further, I have failed to 

 find any figures indicating the presence of sand grains exceeding 

 the fibre in diameter. From the above data, I infer that the 

 sand grains, large or small, are taken in by the fibres at any 

 point of their surface, and at a distance below the growing apex. 



Thalassodendron viminalis, Lendenjeld. 



For the sponge described under this title (No. 365) in my 

 report I propose the name of Echinoclathria intermedia, sp. nov. 

 The fragment of T. viminalis received from Prof. Dendy agrees 

 with the description of the outward form, and is identical in every 

 character with a specimen in the Museum collection labelled 

 Ceraochalina multiformis, var. dura, Lendenfeld (No. 332.) 



The specimen consists of a series of cylindrical branches, from 

 40 to 240 mm. in length, and from 3 to 5 mm. in thickness ; the 

 mode of branching is dichotomous, rarely alternate ; in life the 

 branches were probably arranged in a single plane. The example 

 is somewhat waterworn ; the surface is finely reticulate and 

 is minutely porous, without any trace of vents. The texture 

 firm, tough, and moderately elastic, and the colour brownish- 

 yellow. 



The skeleton, as revealed by the fragment from the British 

 Museum, consists of an axial plexus of densely horny main fibres ; 

 the latter are cored with stylote spicules; there are generally four 

 or five in a row, and their apices are often wide apart. The main 

 column of trellised fibres gives off slender branches, which curve 

 gracefully outwards and terminate at the surface ; these are also 

 cored with styli ; there are two or three in a row ; they are 

 frequently divergent at their apices, and sometimes project beyond 

 the fibre. The axial column and its radiating branches are joined 

 together by slender, transverse connecting fibres ; these are 

 mostly aspiculous. 



The main fibres measure from 1 to 0'15 mm. in diameter ; 

 the radiating branches are 05 to 0'07 mm. in diameter, and from 

 01 to 015 mm. apart. The transverse connecting fibres are 0*2 to 

 0*5 mm. in diameter, about 01 apart. The mesh in the central 

 region is oval or elongate, and gradually becomes quadrangular as 

 the surface is approached. 



The original description states that the fibres are echinated by 

 very scarce smooth styli 05 mm. long, and 0*005 mm. thick. I 

 have not seen any styli that might be safely described as echi- 

 nating ; scattered spicules have been observed, and also some 

 projecting out of the fibres, but these in many cases were enveloped 

 in a sheath of pale spongin, and I regard them as incipient 

 branches. 



