CONKLIN, ACTINIAN LARV/E 



PLATE 3 



Transverse sections of Zoanthella 3.5 mm. long and 1.2 mm. wide. Photomicrographs by H. G. Kribs, taken with monochromatic 

 blue light of 44S fX wave-length. x75. 



Fig. 12. Section through the oral region, showing endoderm filling the coclenieron ; at this stage the mouth is imperforate and the 



pharynx has not formed. 

 Figs, 13-17. Sections through the region of the open coelenteron ; the ciliated b.^nd is plainly divided down the middle. 

 Fig. 18. Section through the aboral region, showing the spongy endoderm filling the entire coelenteron. At various places cells 



are seen in the mesogloea. 



