534 T. A. STEPHENSON 
1900). In their main structural features they form a homo- 
geneous group. In all of them (with rare exceptional indivi- 
duals) there is more than one tentacle situated over at least 
some of the endocoels, and often over all the endocoels and 
even exocoels as well. The contrast between a Stichodactyline 
TEXT-FIG. 13. 
MN SS 
Wsss 
Vertical sections of two sphincters of Stichodactylines. a, Actino- 
porus; B, Aureliania. 
like Cryptodendron and an ordinary form (as regards 
tentacles) like Phyllodiscus is brought out in Text-fig. 2. 
A shows a vertical section of a whole specimen of the latter, 
and passes through one tentacle on each side of the mouth. 
B ig a vertical section through a corner of the oral dise and body- 
wall of the former, and shows many short tentacles cut through 
in the same seetion—they do not all belong to the same mesen- 
terial space, but they have not by any means one space to 
