TWO SPECIES OF PYDRACTINIA 
477 
HYDRACTINIA SODALIS 
Fig. 5 A colony with polyps. Nat. size. 
Fig. 6 Surface view of a portion of a colony adjoining the mouth of shell; 
spiral zooids, young nutritive zooids and blastostyles. 30 diam. 
Fig. 7 Nutritive polyp. 30 diam. 
