LIMNOCNIDA TANGANICiE. 
97 
soon becomes completely separated from the superficial layer 
of ectoderm (Text-fig. 2 , 1 and 2 ). 
I do not, however, agree with G-unther’s further observation 
Text-fig. 2. 
2 a 
Outline sketches of three sections of young medusa-buds : 
1. Longitudinal section showing the formation of the ento- 
codon by invagination with the resulting double- walled cup of 
endoderm. 2. Similar section of a later stage ; the apical 
invagination has now closed up. 2a. Transverse section of the 
same, showing the square entocodon and the constriction of 
the endodermal cup to form four perradial pouches, e. Cavity 
of the entocodon. r.p. Perradial pouch of endoderm. 
that this process of invagination causes the endoderm of the 
bud to be reduced to a single cup-shaped layer of cells 
enveloping tbe entocodon. If a transverse section of a bud 
of this age be examined it will be seen that — (a) the endo- 
