8P0NG1IDA. 459 



tered over surface of fibres, and aggregated into tufts at the ends of 

 the primary fibres. 



Hah. Warrior Eeef, Torres Straits (apparently from beach). 



A single dry specimen ; extreme height 410 mUlim. (16| inches), 

 extreme diameter 480 mUlim. (19-^ inches). This species resembles 

 E. bilamellatum in the regularity of its skeleton and the compact- 

 ness of its fibre. In outward appearance in the macerated condi- 

 tion, however, it has more the aspect of the Arabian form nervosum ; 

 but in this species the frond is only incipiently reticulate and the 

 branches are much stouter. It differs markedly from both in the 

 great length of the echinating spicule, almost half as long again as 

 in those species. 



87. Raspailia bifurcata. (Piaib XL. fig. J ; 

 Plate XLII. figs. I, V.) 



Erect, arborescent ; stem short, 3-4 millim. thick, branching di- 

 chotomously and frequently, in planes usually at right angles to 

 each other and at angles of 30° to 40° ; terminal branches pointed, 

 tapering to points from a thickness at origin of 1 to 1"25 millim. 

 Stem and branches approximately cylindrical. Surface minutely 

 hispid with sharp filiform points, about "3 millim. high and the same 

 distance apart. Texture (in spirit) of stem and branches hard, 

 woody, that of the tips of terminal branches soft and flexible ; 

 colour of stem and lower branches purple, of terminal branches 

 white. Main skeleton composed of longitudinally arranged, sub- 

 parallel loose bundles of the long acuates, accompanied by about the 

 same amount of the acerate, covered and united by a considerable 

 amount of pale purple tenacious material ; the bundles anastomose 

 freely by convergence at small angles ; diameter ranging from about 

 •28 millim. in stem to "05 mUlim. in tips of branches ; surface 

 sparsely covered by the spined acuate scattered over it. No distinct 

 dermis ; the surface is echinated at right angles by tufts, each com- 

 posed of one or more long acuates ; spicules projecting from a conical 

 mass of purple tenacious substance. Sarcode very pale purphsh, 

 transparent. Spicules : — (1) Skeleton acuate, smooth, base well 

 rounded, tapering gradually to sharp points (more rapidly near end); 

 size about 1'2 by -0127 millim. (2) Skeleton acerate, smooth, 

 slightly curved, tapenng to sharp points from about six diameters 

 from ends ; size about "5 to -7 by -0095 millim. (3) Echinating 

 acuate of dermal tufts, as (1), but measuring -022 millim. in thick- 

 ness. (4) Spined cylindrical, tapering gradually from weU-rounded 

 base to blunt distal end, thickly and equably spined ; spines fine, 

 sharp, those of distal part of spicule recurvate ; size "09 by -0079. 



Hab. Prince of Wales Channel, Torres Straits, 5-7 fms.; bottom, 

 shells and sand. 



The specimen on which the species is based is 53 miUim. (2 inches) 

 high and 24 millim. across. The species much resembles Dictyo- 

 eylindrus pikei. Carter, from Mauritius, in form, but, as we have 

 seen, that species is referable to Echinodictyum. 



