Mr. II. J. Carter on tioo iieio Sjjecies o/Gumminege. 23 



ChondriUa australiensis, n. sp. (PI. I. figs. 10-14 & 16.) 



Incrusting, or self-supporting and spreading horizontally j 

 flat, cake-shaped, lobed, of a dirty yellow or buff colour. 

 Surface smooth, slippery, glistening. Consistence semielastic, 

 subcartilaginous, slowly resilient in effacing impressions of 

 the nail, tolerably tough. Vents numerous, small, of different 

 sizes, congregated into groups here and there, or larger and 

 single at the end of a mammiform lobe (figs. 10, c, & 12, g). 

 Pores microscopic, linear, each in the centre of a granuliferous 

 area having the appearance of a lobule, forming altogether a 

 continuous uniform layer presented by the surface generally 

 (fig. 13, a^h). Internal structure consisting of an opaque 

 fleshy mass or body of ovoid cells, surrounded by a translucent 

 cortical rind (fig. 12, Z>, a). Body-mass (fig. 12, h) permeated 

 by branched systems of excretory canals (fig. 12, h)^ which re- . 

 spectively terminate on the surface in the vents mentioned ; 

 scantily charged with siliceous globular stellates of two kinds, 

 most numerous towards the circumference (fig. 12, h). Micro- 

 scojjic structure : Surface consisting of a thin, fibrous cuticular 

 layer, pierced by the pores in the manner above mentioned. 

 Cortical layer translucent, consisting of a trama formed of fine 

 fibres and minute granuliferous cells traversed by the pore-tubes 

 (fig. 12, c?). Trama (fig. 14, a), extending inwards, soon arrives 

 at the opaque body of ovoid cells (figs. 12, Z>, & 14, i), through- 

 out which it is continued, forming for them separate but simi- 

 larly shaped cavities in close approximation (fig. 14, h). Ovoid 

 cell 12 to 15-6000ths of an inch in length, filled or lined with 

 minute cellules (fig. 14, Z»). Surface of the excretory canals, when 

 fresh, apparently provided with the epithelial granular layer so 

 characteristic of the Gummineffi (fig. 15) — but here absent, pro- 

 bably from defective preservation. Pore-tubes frequently in- 

 creasing in size and branching before they have traversed the 

 translucent cortical layer, to become lost in the opaque body- 

 substance, where they appear to join the excretory canals 

 (fig. 12, ee). Commencement of the excretory caiuUs not 

 observed. Spicules globular, siliceous, of two kinds, viz. 

 sphajro-stellate and radio-stellate : — the former, which is the 

 largest, consisting of a clear spheroid covered uniformly with 

 short, sharp, smooth, conical spines arranged pei-pendicularly to 

 the surface (fig. 16, a) ; and tlie latter consisting of several 

 long, conical, s])iniferous rays, bifid and sometimes trifid at the 

 extremities (fig. 16, h). Distrihution: Scattered indiscrimi- 

 nately throughout the mass (fig. 12, 7i), being most thickly 

 congregated, as above stated, towards the surface. Mea- 

 surement : Sphairo-stcllate 6-6000ths inch in diameter ; radio- 



