CLASSIFICATION OF ACTINIARIA 561 
Among the Endomyaria the sphincter, if present, is endo- 
dermal. There are never any acontia. After early evolutionary 
stages are past, there are often vesicles, sometimes very complex 
ones, on the body ; verrucae and acrorhagi are frequent ; and 
in some cases the tentacles increase in number or become 
TrExtT-FIG. 18. 
An enlarged view, from above, of a whole specimen of Phyllo- 
discus indicus. The tentacles are not shaded, and form 
the central part, and projecting beyond them is the corona 
or ruff of compound vesicles. An example of complexity affecting 
outgrowths of the body. 
curiously modified in form-—vesicular or branched, sometimes 
quite feathery in their subdivision. There is little or no 
tendency to thick body-walls of the sort found among Meso- 
myaria, and never are there basal mesogloeal swellings to the 
tentacles. The tentacular musculature rarely becomes meso- 
gloeal. A definite base has been attained save in one case, 
and typically there are basilar muscles. The secondary 
