546 



CRESSWELL SHEAREi;. 

 Text-figs. 1 (>. 



PldOT^occr^*^ 



Xii M.E 



ImrK. 



l.TrX' 



M.E 



l.m.l 



Im.r 



M.E 



M.r 



Text-lig's. l-o. — Early begmentation stages of Planocera (Surface). 

 Text-figs. 4-6.— Pod ark e (Treadwell). E. Ut eiidoderm cell 

 budded off from 4fZo. E'vi.gEntomeres. lin.l. Left portion of the 

 ectomeso))last. l.m-.m. Median portion of the same. J.vi.i: Right 

 l^ortion of the same. M.E. Coelomesoblast. St in. Stomoda'um. 

 Z,,.,. Anal cell. 



