MEM. M. C. Z., IX. No. 3.—ACALEPHS, POLYPS. 41 
being more pronounced below than above, carry the aperture obliquely upward (compare A’). Some of 
the mesenteries are clearly prolonged from the curved portion of the periphery across to the straight — or 
chord — portion corresponding to the line of separation. The latter side subsequently assumes the appear- 
ance of a hilus. 
A view of the base eight days later (J!) shows it almost completely rounded, and in the region of the 
former hilus the formation of two new chambers is confusedly indicated. It is to be seen upon sagittal 
sections that in the region of the hilus some of the mesenteries are certainly formed by the development 
of the distal portion of the central mesenteries of the opposite or curved side, others by the regular growth 
of the mesenteries occupying the folded ends of the off-shoot, and still others by a new local origin ; also 
that the infolded portions previously mentioned gradually come to form the pharynx. 
At length, after six days more (K’, K”), the off-shoot is developed into a minute young actinia with 
nearly central mouth and twelve tentacles. Upon the base are readily recognized six primary chambers 
(1-6), — of which 4 are old and 2 are new, —6 secondary, and 12 spurious chambers. The gonidial cham- 
bers correspond to 1 and 4. 
A few days later it had become quite regular, and showed traces of craspedi (mesenterial filaments) on’ 
the gonidial mesenteries. 
