82 
TH. MORTENSEN, 
(Schwed. Südpolar-Exp. 
Figs. 20 — 22. The apical system and adjoining part of the test of Abattis cavernosus of 6.5. 7.5 and 9 mm. 
length. — Resp. 20, 16 and 14 times magnified. 
each series. — In the posterior lateral ambulacra the first, simple pores inside the 
petals appear in specimens of about 7 mm. length; at about 8 mm. length 2 — 3 
