67 



Fig. a. Two-l'Hyered blastula, endodenn having arisen by de- 

 lamination. 



Plate II. 



Fig. 9, Young planula larva. P, posterior end, a, anterior 

 end. 675/1. 

 " 10. Planula larva; posterior end enlarged; endodermal 

 cells at posterior end arranged along the axis of 

 the larva, marking line of future coelenteron. 



" 11. Two-tentacled polyp, in section; four weeks old. 

 Kc , thickened basal ectoderm. 



" 12. Polyp, four months old, with five tentacles and 

 five oral lobes, lying in the same planes. 



" 13. Polyp, five months old; in typical resting atti- 

 tude, tentacles expanded 2 mm. P.T., prehensile 

 tip of tentacles, adhering to bottom. 



" 14. Five-tentacled polyp, showing form of coelenteron 

 and formation of bud. 



