158 



ZOOLOGY 



SECT. 



colony : it is, in fact, like the horny perisarc of the Leptolianae, a 

 cuticular product of the ectoderm. 



The only other genus to which we shall, refer is Stylaster (Fig. 

 119), which forms a remarkably elegant tree-like colony, abun- 

 dantly branched in one plane, and of a deep pink colour. On the 





