350 COLLECTIONS FROM MELANESIA. 



genus. It has a strong broad base, and tapers rapidly to a point ; 

 in view, however, of its bad condition, I reserve further details until 

 better specimens are obtained. 

 J Jab. Torres Straits, lU fins. 



2G. Callipodium australiense. 



Incrustation very thin, viz. *25 to "5 millim., smooth, varying 

 from dark flesh-colour to dull crimson. Forming either elongated 

 flattened stolons, 3 to 6 millim. broad, or more concentrated in form. 

 Verruca) 2 to 3 millim. apart ; they may be contracted so much as 

 to present mere monticular swellings - 5 millim. high, showing no 

 trace of octoradiate segmentation, or they may form subcylindrical 

 columns 1 to 1-5 millim. high, the octoradiate star occupying their 

 extremities, the walls of the columns being decidedly grooved longitu- 

 dinally along the lines of the segments. Basal diameter of fully 

 contracted verruca? *6 to 1*0 millim., of the more expanded forms 

 just described 1*0 to 1*25 millim. ; apical diameter of the latter 

 about 1 millim. Spicules of stolon : — (i.) Fusiform, generally taper- 

 ing to somewhat slender ends, beset with numerous ( about ten) 

 whorls of prominent tubercles with rounded and minutely tubercu- 

 late extremities, the maximum height of the tubercles being about 

 •03 millim., diameter -018 millim. ; five to six tubercles in each of 

 the central whorls ; average maximum size of spicules *42 by "1 

 millim. (including tubercles), (ii.) Fusiform, tuberculate, the tu- 

 bercles placed mainly on two opposite sides (i. e. in one plane) ; the 

 ends of the spicules are blunt and strongly tuberculate ; the tubercles 

 are about ten in number down each side of the spicule (some much 

 smaller ones on the other faces completing the whorls), but are -042 

 by "035 to -042 millim. in average maximum height and breadth 

 respectively ; rough and often branched ; average maximum size of 

 spicule -52 by -34 millim. (including tubercles), (iii.) Branched 

 spicules, quadri- to multiradiate, the rays either pointed and smooth 

 at ends, or expanding into fungiform terminations ; a few small 

 tubercles on sides of arms ; average maximum extension of arms 

 about -35 millim., diameter of thickest arms or shaft (where present) 

 •04 to -00 millim. 



[The larger of these last forms (iii.) are evidently merely exag- 

 gerated forms of (ii.), and these are but unequally developed repre- 

 sentatives of (i.).] 



Hob. Prince of Wales Channel, Torres Straits, 7 fms. ; bottom 

 sand. 



Obs. This species occurs incrusting a sponge. It differs from 

 Verrill's species C. pacificum and aureum in the superior size and 

 more elongate form of the fusiform spicules and the smaller relative 

 size of their tubercles. I\o " club " or slender " head " spicules 

 observed, as in those species. 



