J. D. Dana on Zoophytes. 7 
33. The various species of Zoophytes having the above gen- 
eral characteristics, differ in the arrangement, number m0 char- 
acter of the tentacles, and the size of the stomach as 
with the whole visceral cavity. In some Zoanthide shi licistish 
is not over one-fifth the length of the internal cavity. Certain 
Actinize have part or all of the tentacles furnished with suctorial 
vesicles for clinging ; and in others they are minutely divided or 
lobed and look like the most delicate embroidery. In a few spe- 
cies ie emt there is a vesicular float contained in a cavity 
ase of the animal to fit it for a sea life, and through these 
pane ed zoophytes approach the Porpita among Acalephs. 
These are only family, generic, or trivial distinctions ; but on 
eis point, the Actinoidea are naturally divided into two Sub- 
34. ‘A part of them have wniformly eight tentacles, and these 
are fringed with minute papilla, each papilla having a puncture 
at aper. ‘These are called the ALcyonarta ; they include the Al- 
cyonia, the Xeniz, (fig. 17,) Gorgoniz, and Tubipores, fig. 18 ; 
the cells of their coralla are distinguished when shioaiects by 
ing simple tubes without rays. 
In others, and here fall the Madrepores and most stony corals 
in addition to the Actiniw, the téntacles are without the papille 
of the Aleyonaria, and the number is six, twelve, or more. "These 
are the AcTINaRrA. The celis of their calcareous coralla are ra- 
the rays rarely becoming obsolete.* eat 
~Intémially the Aleyonaria have om visceral lamella. aaéce 
species of Tubipora examined by the writer, six of them were 
spermatic and two ovarian. Milne Edwards ‘found that in a Ve- 
retillum six of the lamella were spermatic above and ovarian 
below, bearing analogy with a gynandrous plant 
35. The Actinaria are farther subdivided into the ve Anti- 
pathacea, Madreporacea, Caryophyllacea, and Astreeace 
The Antipathacea ee six tentacles; they form a hoonyannié 
but no caleareous co 
The Madreporacea seve twelve tentacles; they form calea- 
reous coralla having the cells small, siz to twelve rayed, with 
the rays seldom obsolete. 
The. Caryophyllacea and Astr@acea have more than sielve 
tentacles, and the cells of their coralla have more than twelve rays. 
Their distinctive characters will be pointed out in the sequel. 
Secretion of the Corallum. 
36. We have already insisted sufficiently on the fact that live 
coral is not a hive of polyps, as the words polypary and polypi- 
dom imply, but on the contrary is a result of animal secretion. 
* They are cheese | in peal Favosites. Yet certain ry species (Favistelle) 
in our American rocks have Ma distin Meg to the 
Sains character es “aléait ni tions b pointed eat by Ehrenberg in his 
oir on the corals of the Red Sea, Cabhand. der Konig. Akad. der Wissensch. 
zu Barina, 18¢ 
