PLATE 4 



EXPLANATION OF FIGURES 



15 and 16 Sections of a very small and faintly colored specimen (later 

 division recorded as no. 82, table 7; an earlier division as no. 64, table 7) having 

 two white bars, but with no orange stripe and showing no external evidence of 

 a division. Figure 1.5 a more oral section; figure 16 one taken below the aboral 

 end of the esophagus. The sections indicate that the specimen is composed 

 almost entirely of two regenerated areas. The older division plane passed 

 through two complete endocoels as indicated by the size of mesenteries c and c. 

 The later division occurred in incomplete endocoels, as is shown by the incom- 

 plete as well as the complete mesenteries. The new incomplete bounding mesen- 

 teries (!) and (7) of the later regenerating area may be seen in figure 16. Both 

 figures X 60. 



17 Section of a small individual (no. 82, table 7) with one white bar (mono- 

 glyphic) and ten evenly spaced orange stripes. There was no external evidence 

 that a division had occurred. The sections make clear that somxwhat less than 

 one-fifth of the specim.en, including no complete mesenteries, is old material, 

 the remainder having regenerated following a division in two incomplete en- 

 docoels. Old bounding mesenteries (II) are incomplete and certaiulj' not of the 

 first incomplete grade. X2o. 



18 Section of a small specimen which has certainly regenerated, as shown 

 by mesenteries c^ and c', but which gives no evidence as to the precise position 

 of the plane of division. X 65. 



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