90 



E. PERCIVAL 



abaxially to the longitudinal muscle. The lip of what is now 

 the rudimentary maimbrium, curls outwards involving the 

 subumbral wall of the endodermal groove. Perradially, where 



Text-kig. 2. 



-C.S. 



Determijiation of number of ephyrae and laying dovm of 

 form of polyp. 



there is practically no groove (PL 6, fig. 12 a) the curling causes 

 a considerable increase in the diameter of the manubrial 

 opening. This, no doubt, has some influence on the formation 

 of the cruciate cavity of the manubrium. As Claus and Heric 

 have shown, a manubrium formed this way has a lining of 



