do no. ,':ivc rise -.u -ou- -. 



o 



..uii vj. ]i.-' b.a'U'^- Uuy.iLiiuU 



at tliG base of the capsule gives rise , like tlio soral 

 segments, to its portion of the dors^.j. i» ui-.j..j x'rom thj 

 ple.'ome of section I • Tiie yomigest one of liicsc gives 

 risu also to a fortcd lateral "bnjullo, formeci n ae ple- 

 •omo of sections III luid IV as in the soral segments 

 (Figs. 3.';, -.). No tvi.ce of tjie placental brancli 0/ pla- 

 cental bundle is seen here, and in tiie o'i her tv;y se.gments 

 no lateral bimdlc is dcvelopod. The plerome of sections 

 II , V yjid YI , in the youngest segment of the three, 

 and p:'obably iJiat of all ".ivd sections except section I 

 of tlic middle segment, is apparently devoted to the fori'i^.- 

 tion of the basal portion of the gelatinous i-ing (g^^^-. 

 Figs. 55, Gr), In i ho oldest or basal seri^nent of the ihree 

 'he plerome and periblem of all the sectioni-; become no''^"- 

 fied to form the basal wall of tv/o layers of thickenuu 

 cells (b.w.. Figs ''^•'•, -'^), lilce the h^'podermal colls of the 

 capsule v/L.ll, and stretching across from vhc dorsal to hv; 

 ventral "iJl. In the periblon of section I in the tv.'o 

 :'oujiger segments, and probably of the first two soral 

 segmc-nts also, '' hore is developed a v/ 11 of thickened colls, 

 like those of the iijupodeiTiiis, enclosing a lens-shaped m:\ss 

 of loss Miickcred cells, the "luns shaped space" of Rv' 

 (i.e.. Fig. ). Into a small oponin^^ aL iiiG lari/e.-io.- 

 end of this sv ^ ■ -ojec: -o' n'' ■h--ni-t — 11-r^ c lis 



