SUB-CLASS III TABULATA—OCTOCORALLA 105 
Stenopora, Lonsd. Branching or lobate coralla composed of fine tubular 
corallites radiating outwards and becoming reflexed. Walls thickened by 
annular deposits of stereoplasma ; tabulae scanty. Abundant in Carboniferous 
and Zechstein. 
Geimitzlla, Waag. and Wentz. Like the preceding, but with walls only 
slightly thickened. Carboniferous to Zechstein. 
? Newropora, Bronn. (Chrysuora, Lamx.), (Fig. 189). Ramose or tuberous 
coralla, composed of long, polygonal tubes, nearly uniform in size, and with 
mouths separated into groups by elevated, non-tubular ridges;  tabulae 
numerous. Jurassic and Cretaceous. 
Family 6. Fistuliporidae. Waagen and Wentzel. 
Encrusting, massive, or branching coralla, composed of two series of fine tubiform 
corallites. Walls compact ; tabulae horizontal ; septa wanting. Autopores multiply- 
ing by coenenchymal gemmation, mesopores by fission. Silurian to Zechstein. 
The Fistuliporidae resemble the Helioporidae in a number of particulars, 
especially as regards the coenenchymal gemmation of the autopores. Waagen 
assigns them to the vicinity of the Helioporidae, while Nicholson regards them 
as a sub-family of the Monticuliporidae. 
Fistulipora, M‘Coy. Corallum composed of two series of tubiform corallites ; 
autopores round or sub-triangular in contour, and embedded in a coenenchyma 
constituted of the smaller mesopores. The latter are much more closely 
tabulate than the autopores, and give the coenenchyma a vesicular, multicellular 
appearance. Walls of the autopores are thickened on one side, and frequently 
provided with two septa-like processes. Common in Devonian, Carboniferous, 
and Permian. 
Callopora, Hall; Prasopora, Nich. Ordovician and Silurian.  Labechia, E. 
and H., occurring in the Ordovician and Silurian, probably also belongs here. 
Geological Range of the Tabulata. 
With but few exceptions, the Zubulatu are restricted to the Palaeozoic 
formations, and from the Ordovician to the Carboniferous periods inclusive are 
prominently concerned along with the Tetracoralla and Hydrozou (Stromatoporidae) 
in the building of coral reefs. Of the six families composing the Tubulata, the 
Hulysitidae alone are confined to the Silurian; the rest are all more or less 
plentiful from the Ordovician to the Carboniferous ; while the /istuliporidae 
persist as late as the Zechstein, and the Chaetetidae range from the Ordovician 
to the Cretaceous. 
Sub-Class 3. OCTOCORALLA. Haeckel. 
(Octactinia, Ehrenberg ; Alcyonaria, Milne-Edwards. ) 
Composite colonies, rarely simple polyps, the individuals provided with eight 
mesenterial folds and eight broad, pinnately fringed, or plumose tentacles, which form 
a single cycle about the mouth. 
Hard skeletal elements are very generally developed in the Octocoralla, being 
absent in comparatively few forms, and are remarkable for their manifold 
