318 DECEMBER. 



the most part somewhat blunt, but some are very sharp. 

 After death it rapidly loses its brilliant hue, and dries 

 of a dull oak- brown. 



Another occurs in the form of low irregular spreading 

 patches of a greyish black, very smooth and shiny, 

 more plump than the former, and a little larger. 1 There 

 are no visible orifices on the surface. The substance 

 is yellowish grey, compact, with a distinct demarcation 

 from the thin black tough skin. The spicula of the 

 flesh have three rays in one plane, and one standing up 

 from it; very stout, sharp-pointed, with a distinct 

 canal running through the centre of each ray of the 

 larger ones. There are a few rods abruptly hooked at 

 the tip ; a few very long, straight, and slender, with pin- 

 like heads ; and a few simple needles, long, slender, 

 pointed at one or at both ends. 



Some largish rounded masses occur, several inches in 

 diameter, and rising to a thickness of three-fourths of 

 an inch. 2 The surface is undulate, the summits slightly 

 ridged, covered with shallow sinuous channels having 

 sharp edges, not very confluent : large round mouth- 

 orifices (oscula) generally mark the summits of the 

 ridges. The colour of this fine species is a deep buff, 

 and its appearance is much like that of our Turkey 

 Sponge, with something of the same feel, but much 



1 Halina Bucklandi. Halichondria incrustans. 



