p. 1

Clathropora flabellata; Hall, Foster & Whitney's Geol. of L. Sup. part 2 p. 207 pl. 24 fig. 2

Frond expanded flabellate, somewhat plicate towards the base; perforated by numerous roundish, or oval openings of variable sizes; cells minute; rhomboidoval, arranged between obliquely ascending lines or laminae; axis concentrically striated and corrugated around the perforations. Resembles C. frondosa but the frond is thinner, & the perforations larger & less regular; & the cells are more oval or elongated.