364. C. M. Child 
all of the preceding cases oral-aboral tentacles occur and in all 
except No. I and the longer group in No. II the mesenteries ac- 
quire a more or less perfect radial arrangement about a point 
corresponding to the center of the group of tentacles. 
6 
S 
Leo 
20 
Fics. 17-20 
Cases with Tentacles only on the Oral Side of the Line of 
Union 
Most of these cases appear much like the preceding, except as 
regards the position of the tentacles with respect to the line of 
union. In these cases none of the tentacles are oral-aboral and 
none are aboral, but all arise from the original oral end of the body- 
wall. It is interesting to note, however, that those which lie 
