\\ 
Yy \ 
PLATE XII. 
LETTERING ON THE FIGURES. 
col. w., . column wall. (Oye O36 - mesentery. 
c. 18. cell-islet. m. file, mesenterial filament. 
@ Bog ciliated streak (Fimmerstreif). MES, - mesoglea, 
CU, cuticle. mg. st.,. marginal stoma. 
d., directives. Mr. Mey macrocnemic mesentery. 
disc, dise. nem., nematocyst. 
Olay ectoderm. nr. l., nerve layer. 
ect. can., ectodermal canal. 0b. m., . oblique muscle. 
ect. M.,. ectodermal muscle layer. p. b. m., parieto-basilar muscle. 
ene. s.,. . . . . encircling sinus. per. Ste, perioral stoma. 
end., endoderm. 7m. Cte, reflected ectoderm. 
end. m., endodermal muscle layer. r. Me, retractor muscle. 
Flds Ue fibrillar layer. T. Ss, reticular streak. 
Sos., fossa. So Che sulear directives. 
Gh Pox meme landecells sl. d.. sulcular directives. 
I. G5 gonidial groove. Spey « spermarium. 
Fo Sp glandular streak. sph. m., sphincter muscle. 
(Driisenstreif, Nesseldrisenstreif). st., stomodeeum. 
ine., incrustations. tent.. tentacle. 
Bo Bb intermediate streak. 200%., zooxanthelle. 
lac., . . lacune. Top Won Thi Wn o orders of mesenteries or tentacles. 
Figure 
1. Ricordea florida. 
2. 
3. 
4, 
5. 
6. 
Uo 
Transverse section through the stomodeal region of a polyp in which the 
mesogleal plaitings for the support of the retractor muscle are displayed, as also the irregular 
development of the pairs of mesenteries of the third order. Three pairs of perfect mesenteries 
occur on the one side of the directives and four pairs on the other. x 12. 
Transverse section through a portion of the column-wall and a mesentery of 
x 320. 
Ricordea florida. 
the first order. 
Actinotryx Sancti-Thome. Transverse section through a fertile mesentery with ripe spermaria in 
act of dehiscing. x 75. 
Homostichanthus anemone. Plan of tentacular arrangement. An outer series of cycles in which 
the same number of tentacles occurs in each endoceele and exocele can be distinguished from 
an inner series in which the cycles are imperfect, and more separated one from the other. 
Homostichanthus anemone. Radial section of portion of column-wall. x 320. 
Homostichanthus anemone. Tangential section through the periphery of the disc and uppermost 
region of the column-wall. The portion represented is but shghtly tangential, so that only 
two mesenteries are cut through, and two tentacles are in communication with an exocele 
The mesogleal plaitings supporting the restricted sphincter 
x 25. 
and two with an endocele. 
muscle are a little longer in a truly radial section than are here represented. 
Corynactis myrcia. Plan of tentacular arrangement. 
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