SPONGES.-HALLMANN. 26^ 



stouter-spiculed specimens, but in any case they are scarce 

 and in the first-mentioned two specimens have not been 

 observed. 



(ii.) The auxiliary tylostyli are normally straight, but in 

 some specimens a considerable proportion, perhaps even a 

 majority, are variously flexed. They range in length from less 

 than 160 to (usually) slightly more than 300 >t ; their greatest 

 observed length in any specimen was 350 ji. 



I have quoted Antherochalina tenuispina, Lendenfeld, as a 

 probable synonym of O. tenuis on the evidence of a small 

 piece of a British Museum specimen labelled with the name 

 and locality {viz.. Western Port, \'ictoria) of Lendenfeld's 

 species. As the fragment conforms in external features with 

 Lendenfeld's description, I have but little doubt that the name 

 attached to it is the correct one, and would say, therefore, that 

 in respect of its spicular characters .4. tenuispina has been 

 wrongly described. 



In some features of the skeleton O. tenuis resembles 

 Clathria (?) chartacea, Whitelegge {vide p. 208) — a species 

 from which, externally, it appears to be indistinguishable. 



Locs. — Port Philip, 18-20 fms. {Carter; Dendy ; Austr. 

 Mus. Coll.); forty miles west of Kingston, South Australia, 

 30 fms. ("Endeavour"). 



Ophlitaspongia inornata, sp. nov. 

 (Plate xxxvi., fig. 2, and fig. 57.) 



Sponge stipitate, ramose; branches short and crooked, 

 mostly confined to one plane, sometimes anastomosing. 

 No apparent dermal membrane. Osciila doubtfully 

 present. Skeleton: In the older parts of the sponge, the 

 axial region of the branches is occupied by a dense plexus 

 of stout, generally aspicidous, horny fibres, by a pro- 

 fusion of longitudinally-disposed extrafibral spicules 

 {principal styli) arranged in loose bundles and strands, 

 and by single spicules which, though generally scattered 

 without order, appear in places as if arranged reticulately. 

 From the axial region there run outwards and upwards 

 to the surface, fibres with divergingly disposed and fre- 

 quently echinating spicides which, at the extremity of the 

 fibre, form a projecting tuft; these fibres are joined by 

 transverse and interreticulating paucispicular connecting 

 fibres forming with them rectangular and polygonal 



