r 



CORALS AND BRYOZOA. 235 



lated, and there are no mesopores. This form, in its general features, has sim- 

 ilar relations to the genus Fistulipora that Selenopora has to Lichenalia. 



Formation and locality. Shales of the Hamilton group, York, Livingston 

 county, N. Y. 



CERAMOPORA, Hall. 1852. 



(See page 33.) 



Ceramopora ? (Lichenalia) foliacea. 



PLATE LVII, FIGS. 6, 7. 



Lic)ienalui foliavea. Hall. Trans. Albany Institute, vol. x, \^. 183. 1881. 

 " " " Report of State Geologrist for 1883, p. 35. 1884. 



ZoARiUM consisting of a thin, foliaceous expansion, attached at the center to 

 other bodies, the greater portion of the frond being free ; under surface a 

 thin epitheca, with strong concentric wrinkles, and radiating striations 

 caused by the recumbent portions of the cell tubes. Cells tubular, gradually 

 enlarging to the aperture, oblique to the surface. Intercellular tissue vesicu- 

 lose. Cell apertures circular or broadly oval, diameter .33 mm., the width equal 

 to three-fourths the length ; on a plane with the surface or oblique, disposed 

 in diagonally intersecting rows, usually alternating and imbricating. Peri- 

 stomes moderately thick, sometimes equally elevated, but usually the pos- 

 terior portion is the more strongly elevated and oblique, the upper part of 

 the cell walls being sometimes exposed for a distance equal to the diameter 

 of an aperture, or even more, angular and carinated, giving to the aperture 

 a sub-triangular form. Liter-apertural space smooth. Surface marked by 

 elongate maculse, which are destitute of cell apertures, and occur at some- 

 what irregular intervals. The apertures immediately adjacent to these are 

 larger than the others, having a diameter of .50 mm. 



This species differs from Ceramopora explanata, of the Niagara group, in hav- 

 ing smaller cells, which are less closely disposed, and less distinctly alternating 

 and imbricating ; the maculae are much more distant and are destitute of cell aper- 

 tures : from Lichenalia stellata it diflfers in having the apertures more regularly 

 arranged in alternating and imbricating order ; the maculas are not elevated 



