94 Cincinnati Soeieti/ of Natural History. 



and strongly wrinkled dermatic crust. Branches from 3 to 10 lines iu 

 diameter, the inner or inferior side lined with a very thick epitheca; 

 the substance of pol^^zoary surrounding the hollow part from 1 to 3 

 lines in thickness. 



Surface smooth, or carrj'ing low, broad monticules, distant from each 

 other about 1|- lilies; their summits occupied b}' large maculiv, con- 

 sisting of from 30 to 80 minute tubuli. Tubules arranged in regular, 

 alternating series, about six in the space of one line, with apertures 

 I'homboidal in outline, and in the perfect state, slightly raised and 

 arched. Intertubular spaces thin, and almost completely destitute 

 of minute cells, excepting the cellulose maculse before mentioned. 



Sections show tubules prostrate at first, and then bending rectangu- 

 lar to the surface. Diaphragms in these, straight, and generally twice 

 the diameter of a tube apart. Diaphragms in the minute tubes close 

 together. 



This species is very distinct from any species of the genus heretofoi'e 

 described. From C. jamesi, to which it bears some resemblance, it is 

 distinguished by the regular arrangement of its cells, and the cellulose 

 maculiB; the latter are not represented in that species. 



Locality and Position. — In the lower part of the Cincinnati Group, 

 at Covington, K}'., from low water mark to 100 feet above that 

 elevation. It is also found at Frankfort, K}'. 



Ptilodictya perelegans, n. sp. (Plate IV., figs. 16 and 16a.) 



Folyzoary frequentl}^ and alternately branched, sharp edged, the 

 branches being acutely elliptical in cross section, about one quarter of 

 a line in thickness centrally, and one and a quarter line wide. Cells 

 covering the surface on both sides, with the exception of a rather broad 

 non celluliferous border lining the branches. The bases of the cells on 

 the two aspects of the frond are separated by a thin laminar axis. 

 Cell-mouths circular, with a conspicuously elevated rim, arranged in 

 transverse rows, as well as in very regular intersecting diagonal lines, 

 which form an angle of about thirty degrees with the sides of the 

 branches; about seven cells in the space of one line measuring both 

 longitudinally and transversely. 



Intertubular spaces quite as wide as the cell-openings, and orna- 

 mented, when perfectly preserved, by slightly raised and flexuous 

 lines. The non-poriferous border occupies, on each side, about one 

 seventli of the entire width of a bi-ancli, and is marked with very fine, 

 and but slightly waved striae, the direction oi' which forms an angle of 

 about fifteen degrees with the mnrgin of the branches. 



This beautiful species is allied to 1'. (Stictopora) elegantula, of Hall, 

 ))ut that species does not branch so fro(\u('ntly, has the cell-mouths 



