70 



COELENTERATA 

 Dorsal 



[CH. 



Ventral 



FIG. 30. Transverse section through a polyp of Alcyonium digitatum below the 



level of the oesophagus x about 120. From Hickson. 



1. Coelenteren. 2. Mesentery with free edge. 3. Ectoderm. 4. Meso- 

 gloea or jelly. 5. Endoderm. 6. Muscles in mesentery. 



Dorsal 



2 



Ventral 



Transverse section through a polyp of Alcyonium digitatiun, through 

 the region of the oesophagus x about 120. From Hickson. 

 Cavity of oesophagus. 2. Siphonoglyph. 3. Ectoderm. 4. Meso- 

 gloea or jelly. 5. Endoderm. 6. Muscles in mesenteries. 7. Inter- 

 mesenteric cavity. 



FIG. 81. 



1. 



