21 



The oblique, rhomboid cell is seen wherever a regular growth 

 took place. 



Length of cell from one-sixteenth to three-sixteenths of an 

 inch; about ten cells to one-eighth of an inch. 



From the upper part of the shale. 



TUBERCULOPORA (N. Gen.) 



Corallum composed of a solid surface, covered with large, 

 irregularly rounded tubercles, upon the surface of which are 

 one or more circular, isolated cells, where they open abruptly. 



Tubercles, where large, increase in size above the surface 

 from which they rise, and are apparently simple, unicellular in 

 their origin; but afterwards increasing by lateral budding or 

 coalescing. Cells increasing in size from below up as the 

 tubercle increases. 



TUBERCULOPORA INFLATA (N. Sp.). PI. 2, fig. 18. 



Corallum ramose, central, or stem portion, solid, and comprises 

 one-half of the whole diameter of the frond; it has a small, 

 round axial opening about the size of one of the larger cells; 

 upon this are placed large, irregular, rounded, inflated looking 

 tubercles or papillae, of the same solid character as the axial 

 portion; and as they seem to be of unicellular origin, the irreg- 

 ularity in prominence, size and shape is due to the coalescence 

 of two or more as they increase in size and meet by lateral ex- 

 pansion and also by lateral budding of the tubercle, as is shown 

 by the comparatively small cells existing in the smaller nodes 

 placed on the sides of the larger tubercles. Cells circular, of 

 various sizes, each commencing as a mere point on the axial 

 surface, or the lateral surface of a larger tubercle; and widens 

 out as the tubercle forms around it, and are lined by a well 

 defined envelope; sections of which exhibit a distinct fibrous 

 structure which radiates from the cell at right angles; differing 

 markedly from the surrounding coralline structure which radi- 

 ates from the center towards the periphery and does not show 

 any decided fibrous structure. 

 2 



