Observations upon Stenopora fibrosa, etc. 369 



between the old ; tubes constricted at irregular distances in planes par- 

 allel with the surface, and partially closed at the orifice by a concave 

 diaphragm, perforated in the center ; no connecting tubuli nor for- 

 amina. 



In some species the tubes are polygonal throughout, in others they 

 are polygonal in the middle where closely packed, and round near the 

 surface where further apart. The interior of the tubes exhibits only 

 imperfect diaphragms, perforated in the middle. 



Stenopora fibrosa— {GoiSD¥\]BB, 1826). 



Corallum polymorphous, usually forming cylindrical branches com- 

 posed of polygonal tubes (usually six in the space of one line), slightly 

 and irregularly flexuous, nearly straight in the middle, abruptly bend- 

 ing outward to the surface, near the sides ; edges and sides smooth, or 

 marked in parts with strong, close irregularities of growth, forming 

 tubercles on the angular edges and wrinkles across the sides ; young, in- 

 terpolated tubes rapidly reaching their full diameter ; substance of the 

 tubes thick, the interior cylindrical, traversed by numerous diaphragms, 

 at irregular distances, usually the width of the tubes apart, sometimes 

 in places irregularly crowded ; surface having a net-work of polygonal 

 ridges, with an inner concave space, in which is the small round aper- 

 ture. 



This species was founded by Goldfuss, in 1826 (Petrefacta, pp. 82, 

 215, tab. xxviii, figs. 3 and 4; tab. xxiv. fig. 9), upon speci- 

 mens obtained from Lexington, Kentucky. The branching forms of this 

 species are the most common and abundant corals found about the 

 Cincinnati quarries. 



Stenopora lycoperdon — (Say). 



Corallum massive, hemispherical or subhemispherical, growing from 

 a flat, expanded, round or somewhat oval, membraneous, concentrically 

 wrinkled base. Tubes minute, fiber-like, traversed by diaphragms, and 

 in all other respects corresponding with Stenopora fibrosa. The size, 

 form, and concentrically wrinkled base are the only characters by 

 which these two species can be distinguished, if indeed one is not 

 merely a variety of the other. 



Prof. Hall, in the description of this species under the name of 

 Chetetes lycoperdon, in the first vol. of the Paleontology of New York, 

 says, that the " coral increases by subdivisions of the parent tube, or 



