No. 1.] ACTINIARIA OF THE BAHAMAS. 25 
reticular structure, there being here and there areas of mesogloea 
of varying size. Towards the exterior the mesogloeal processes 
cease to anastomose, and run radially toward the surface of the 
thickening. The thickening thus appears to be composed of 
two parts passing gradually into each other, a central part of 
reticular structure, and a peripheral part composed of mesoglceal 
processes arising and radiating out from the reticular portion. 
The muscular layer throughout the rest of the column is weak, 
and the mesoglceal layer is comparatively thin. The endoderm 
throughout contains numbers of “yellow cells” and a dark 
pigment which persists in preserved specimens, and is therefore 
not soluble in alcohol nor destroyed by weak nitric or chromic 
acids. 
The margin is furnished with acrorhagi, slightly tuberculate 
upon their outer surfaces; they are simply the enlarged upper- 
most turbercles. The tentacles are not very long, the inner 
ones measuring about I.9cm. They are entacmzous, cylindri- 
cal, and arranged in five cycles, their formula being 6, 6, 12, 24, 
48, there being thus 96 in all. In cross section the thinness of 
the mesogloea and the absence of any muscular processes are 
noticeable. 
The ectodermal musculature of the disc is not particularly 
strong, the mesogloea being raised into processes of no very 
great height. There are no enclosures of muscle cells in the 
mesoglcea as in 7ealia crassicornis. 
There are altogether 48 mesenteries, and of these 24 are 
perfect and 24 imperfect ; 12 of the perfect ones, however, are 
not attached quite so far down the stomodzeum as the other 12, 
to which latter series the directives belong. The longitudinal 
and parieto-basilar muscles are present, but show no peculiarities 
calling for special mention, except that the former are by no 
means so prominent as in TZealia crassicornis or bunodiformis. 
All the mesenteries, with the exception of the directives, are 
gonophoric. I was not able to discover any mesenterial stomata, 
though it appeared as though the inner ones were present. 
Before I had concluded my study of this form I felt inclined 
to identify it with the European B. gemmacea. The extension 
of the geographical area inhabited by that species by such an 
identification seemed a much slighter obstacle than certain 
structural discrepancies, some of which, however, seem to be in- 
