EY R. VON LENDENFELD, PH.D. 1107 



radial. Tangental rays 0-1 — 0-3 5 x 0-305 mm., cylindrical slightly 

 bent, pointed. Centripetal ray 0-04 — 0*08 x 0-007 mm. shorter 

 and thicker than the tangental ones. Triradiates of the Parenchyma 

 sagittal, basal ray 0-2 x 0007, lateral rays slightly curved 009 — 

 0-12 x 0-007 mm. There are 2-3 layers of these spicules in the 

 body-wall. The cortex contains triradiates and acerates. The 

 former are mostly regular, disposed tangentally the three rays 

 nearly in one plane cylindrical, pointed 0.09 — 0-12 x 0-007 mm. 

 The Acerates are bent on the outer end rectangularly so as to attain 

 the shape of hooks. The longer portion is immersed in the sponge 

 with its proximal two thirds and stands vertical on it and measures 

 0-2 x 0-014 mm., the bent outer part - 05 x 0-014 mm., centripetal 

 end conic, both pointed. The outer part of these Acerates points 

 towards the Osculum. 



Locality : East Coast of Australia, Port Jackson, V. Lendenfeld ; 

 Europe, E. Haeckel. 



13. GENUS. HETEROPEGMA. Polejaeff (1). 



Grantinse with a highly developed cortex containing triradiates 

 and quadriradiates, totally different from those of the Par-enchyma, 

 ciliated tubes much branched. 



25. SPECIES. HETEROPEGMA NODUS GORDII. Polejaeff (2.) 



This species forms colonies of a rather Asconoid appearance. 

 The tubes, sometimes standing vertically, sometimes lying horizon- 

 tally, ramify and interlace, thus constituting a kind of knot in 

 which neither beginning nor end can be discerned. The indivi- 

 duality of the tubes is expressed only by Oscula, these latter being 

 naked. The size of the Oscula is inconstant, varying from 0-25 

 mm. to 1 mm. in diameter. Both the surfaces ai-e rough. The 

 average thickness of the wall is 1 mm., the diameter of the inner 

 cavity 1 to 2 mm. The radial tubes are of irregular outline, and 

 show a great tendendy to ramify. 



(1.) N. PoUjaeff. L.c, 25-45. 



(2.) iV. Polejaeff. L.c, p. 45, pi. I., fig. 7 ; pi. IV., fig. la-Id. 

 72 



