Eschara. 
Z. ASCIDIOIDA. 
299 
again, leaving certain hollow spaces between them ; their cells are 
much smaller, though of the same shape with the cells in the folia- 
ceous Millepore” (E. foliacea). Solander .—- Pallas maintains that 
it is merely a variety of the preceding ; but Milne-Edwards thinks 
it ought to be retained distinct, for its peculiarity of ramification, and 
the narrowness of the divisions, do not depend on age, and seem to 
indicate a specifical difference. The cells in both are alike. 
