POLYZOA. 67 



the cell, they are protected above by a membranous comb-like 

 friU. 



The cells either bud off from each other or arise as buds on a 

 stolon or stem. 



Altyonidium gelatinosum^ (Fig. 17), so called from its resemblance Case A, 

 to the zoophyte Alcyonium, forms fleshy translucent growths "art^*^^ 

 occurring in the form of nodulated branched masses, or of long 



Fisr. 17. , 



part. 



Alcijonidmm gelatinosum. A, a small piece, natural size ; B, the 

 same magnified. 



finger-like growths. The species is common round om* coasts 

 where it grows attached to stones and shells near low-water 

 mark. 



Amafhiaiovms, bushy growths composed of slender horny branches. 

 The cells, which are cylindrical or squarish, rise from the branches 

 in biserial rows like Pan's pipes. In Amathia lendigera * (Fig. 18) the case A, 

 groups of cells are well separated from each other, but in A. spiralis* upiight 

 and A. convoluta* the cells form a nearly or entirely continuous series 

 winding in a spiral round the slender stems. In BoiverlanMa 

 inibricata* the cells are clustered on the stems. Vesiciilaria spinosa*, 



F 2 



