486 REVISION OF THE AXINELLID^, 1., 



base, three secondary branches which become coalescent with one 

 another. R.N. 297 is unique in consisting solely of a long 

 slender unbranched stem, 250 mm. in length. In both speci- 

 mens the extremities are tapered. Jn neither were niicro- 

 strongyla observed. 



Trachycladus pustulosus, sp.nov. 



(Pl.xxi.,fig.5; PI. xxvi., figs.5, 8; PI. xxvii. fig.6; PI. xxxix., 



figs.6, 7.) 



1887. {1)Spirophora bacterium Lendenfeld(26), p.795. 



Diagnosis. — Branches quite short and distally expanded; 

 sometimes so abbreviated as to be little more than mammifoim 

 lobes. Surface closely studded with small pimple-like elevations, 

 and exhibiting, on close inspection, a minute reticulate pattern 

 due to the mode of arrangement of the dermal pores. Oscula 

 situated only on the more distal parts of the branches. Dermal 

 pores arranged in close-set, subcircular, sie\e-like groups, usually 

 with from 3 to 7 pores in each group. Dermal layer loosely 

 packed with spirulse usually throughout its entire thickness— 

 which varies from 40 to 80/x. Skeleton in the upper, more ex- 

 panded, parts of the branches not forming an axial fune. Fibres 

 stout, and provided with much spongin. Megascleres in the 

 upper parts of the branches consisting almost exclusively of 

 strongyla and oxea in about equal numbers, and rarely attaining 

 to 320 X 9/x in size; peduncular megascleres chiefly oxea (together 

 with occasional styli and only rare strongyla), attaining a 

 maximum size of 460 x 15/x. Microstrongyla extremely abund- 

 ant, frequently assuming various abnormal shapes, and in part 

 reduced to spheres. 



Loc. Port Phillip. 



This species, — of which two well-preserved specimens are at 

 hand, one incomplete, consisting only of a few branches, — is 

 characterised especially by its short stunted branches and very 

 noticeably pimpled surface, and by the fact that the skeleton, 

 except in the stalk and the lowermost part of the longer branches, 

 is only slightly or not at all condensed axially (PI. xxxix., fig.6). 

 Whilst these features sharply mark it off from all the other 



