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SOME PROBLEMS OF COELENTERATE ONTOGENY 507 
tion they fused and remained for some time. Fig. C shows the 
condition when the four-cell stage -had been established. As 
will be seen, the blastomeres had rotated until they became, as 
it were, fitted into close contact with each other, and the devel- 
opment of another connective bound them in that relation for 
some time. It may be noted that later development went for- 
_ ward with average regularity. 
2. Kctosarcal features. In my paper on Pennaria (’04b, p. 
469) attention was directed to certain very conspicuous aspects 
which were designated as ‘ectosareal phenomena,’ and which 
comprised various more or less superficial excrescences, such as 
papillae, films or bridge-like connectives between blastomeres, 
