1... permanent _ 
ectoderm of 
the manubrium. 
endodermal core” 
of manubrium 
excavation for ---- 
subumbrellar cavity. 
oesophagus ----- 
coelenteron of the 
hydroid polyp. 
2 oes. 
] 
GH. 
H. Fowler del. ¥ Huth, Lith? Edin? 
