col. wW.,. 
O Gp 
2 Bop 
Cu, . 
d., 
dise., 
ect., 
ect. can., 
ect. m., 
Qs Sop, 
end., 
end. m., 
fb. 1., 
HO8oy 0 
gl. ¢., 
Go GPa 0 
Gass, 
$n0., 
Os By 
lac., . 
Figure 
1. Ricordea florida. 
stomodeal region, showing the imperfect mesenterial filament. 
bo 
go 
HS 
On 
. Actinoporus elegans. 
Corynactis myrcia. 
PLATE XIII. 
LETTERING ON THE FIGURES. 
column wall. 
cell-islet. 
ciliated streak (Flimmerstreif). 
cuticie. 
directives. 
dise. 
ectoderm. 
ectodermal canal. 
ectodermal muscle layer. 
encircling sinus. 
endoderm. 
endodermal muscle layer. 
fibrillar layer. 
fossa. 
gland cell. 
gonidial groove. 
glandular streak 
(Driisenstreif, Nesseldrtisenstreif). 
incrustations. 
intermediate streak. 
lacune. 
x 820. 
200K, 
Mop 1h Wb) CAOy) 
stomodeum first terminates opposite the pair of directives. 
connexion they retain around their free edge a tissue like that of the stomodzal ectoderm 
which passes insensibly into the mesenterial filaments. 
x 50. 
. Corynactis myrcia. Transverse section through the stem of a tentacle showing the brush-like 
character of the fibrille radiating from the mesogleeal folds. 
mesentery. 
mesenterial filament. 
mesoglea. 
marginal stoma. 
macrocnemic mesentery. 
nematocyst. 
nerve layer. 
oblique muscle. 
parieto-basilar muscle. 
perioral stoma. 
reflected ectoderm. 
retractor muscle. 
reticular streak. 
sulcar directives. 
sulcular directives. 
spermarium. 
sphincter muscle. 
stomodeeum. 
tentacle. 
zooxanthelle. 
orders of mesenteries or tentacles. 
Transverse section towards the free edge of a mesentery a little below the 
x 250. 
Transverse section through a portion of the column-wall and of a mesentery, 
in the upper region of the polyp. 
Radial section through the infolded region of the column-wall. x 250. 
. Corynactis myrcia. Transverse section through a portion of a polyp near the aboral termination 
of the stomodeum. The stomodwal wall is folded backwardly and outwardly upon itself, so 
that it is here cut through twice, and the enclosed endoderm is shown on the left side. The 
As the mesenteries cease their 
x 820. 
6. Actinoporus elegans. Radial section through the upper part of the polyp. Slightly reduced. 
7. Parazoanthus tunicans. Radial section through the distal region of the column-wall. x 75. 
8. Parazoanthus separatus. 
9. Parazoanthus monostichus. 
Vertical section through the base. 
[ 216 ] 
x 250. 
Transverse section of a polyp through the elevated peristome and 
capitular region. The peripheral tissues are disorganized as a result of the presence of the 
numerous circularly-arranged sponge spicules. x 75. 
