730 Scientific Proceedings, Royal Dublin Society. 
something of it with the naked eye.”” In my specimens, this 
thickening of the mesoglcea at the site of the sphincter is very 
trifling ; indeed, scarcely noticeable. Further on, p. 44, still 
speaking of the sphincter, he says :—“ The mesoglcea does not rise 
as in A. sulcata and Antheopsis roseirensis into more or less high 
folds, but preserves an entirely smooth surface towards the 
epithelium ; moreover the muscle fibres grow deeply into it, and 
appear at times to become wholly mesogleeal. One may regard 
the singular condition of this sphincter as being in a certain sense 
a transition or middle stage between an endodermal and a meso- 
gleeal sphincter ; the latter is at once attained if one thinks of the 
base (Fussteil) of the muscular twigs as absent.” I can find 
nothing in any of my specimens, when the sections are vertical, 
which would justify me in saying that the sphincter in Actinia 
equina is anything but endodermal. Oblique sections either of 
the sphincter or the tentacles often give the effect of mesoglceal 
muscle. . 
Speaking of the ectodermal muscles of the oral disc, on p. 44, 
he says:—“ They attain their greatest height in the middle 
between the insertion of two septa, and form here in tangential 
sections through the disc, pretty, rosette-like structures ; the radial - 
swellings of the dise apparently rise from these.’”’ These “ rosette- 
like structures” are seen in tangential sections of my specimens, 
but I believe they are due to the sections passing somewhat 
obliquely through the base of a tentacle of a different cycle from 
those obviously cut in the section, as on following these ‘rosettes ”’ 
through several sections, they pass gradually into sections of 
tentacles. On p. 45, the statement is made that “ zooxanthellae 
were observed nowhere in the bodies”; in all the specimens I 
examined down to embryoes of the 8+ 4 stage, the endoderm is 
everywhere crowded with zooxanthelle. I notice, on p. 46, that 
“‘all the septa, except the directives, bear gonads’’; also that all 
the septa are. covered with mesenterial filaments ; it is evident that 
Simon’s specimens were older than mine, as in the largest I was 
able to examine the fifth cycle of mesenteries bore no filaments, 
and were incomplete in number. Simon does not state the exact 
number of fifth-cycle mesenteries found in his specimens, but, as 
he says “they are regularly arranged” (p. 45), I conclude that 
they had attained their typical number of forty-eight. 
