322 DECEMBER. 



but frequently swollen and contracted by turns. These 

 are not tubular, and the tips are rounded. The general 

 surface under a magnifier appears slightly channelled. 

 Within we find simple needles, long, nearly straight, 

 pointed at both ends, moderately numerous, enveloped 

 in much yellow granular flesh. 



Then there are some imposing masses of a globose 

 form, 1 some of which attain a foot or more in diameter, 

 though others are not more than an inch. The surface 

 is compact and smooth, of a delicate purplish-grey hue, 

 with a few minute orifices, each surrounded by a small 

 paler area. 



The spicula in this noble species are various : simple 

 rods, straight, thick, long, slightly spindle-shaped, blunt 

 at both ends, with a linear axis; three -rayed, large, 

 stout, very unequal angled, without any central channel ; 

 a number of very small five- and six- rayed stars, the 

 rays projecting in different planes. They are set in a 

 dense, yellow, gelatinous flesh, in which we may at all 

 times discover many gemmules, or eggs; the smaller 

 (or younger) are nearly round, bristling with points in 

 all directions like sea-urchins, changing as they grow 

 larger to a more oval form, beset with rounded warts, 

 instead of points. These are discharged, when mature, 

 with the currents of water, through the orifices, and 



i Pachymatisma Johnstoni. 



