18/8.] The Paleontologist. 



Ptilodictya paralella. (James.) Polyzoary a flattened, linear, unbranched, two- 

 edged frond, about one line wide, longest example observed one inch. Surface gently 

 convex celluliferous on both faces; edges very thin and sharp. Eight or ten alternating 

 rows of elliptical cells arranged between longitudinal lines; one row on each edge having 

 an oblique direction. Cell apertures not raised, five or six in the space of a line measur- 

 ing longitudinally. 



Locality — Cincinnati. 



GENUS CERAMOPORA, (Hall.) 



Ceramopora, (?) Beani. (James.) Polyzoary forming thin, irregular expansions 

 upon the surface of Orthoceras aiid other foreign substances. The cells have, sometimes, 

 central points from which they radiate, and are arranged in a somewhat quincuncial order 

 in alternating oblique rows; but in other cases they are not so arranged. Cell walls 

 rather thick and not raised above the general surface; apertures slightly oblique in some 

 cases. Cell apertures generally long oval or diamond-shaped, but sometimes quite irregu- 

 lar in form. About three cells in the space of a line measuring the longer diameter, and 

 four or five measuring transversely. In some cases the cells and cell walls resemble the 

 nonporiferous face of the fenestrules and branches of Retepora. Placed doubtfully in the 

 Genus Ceramopora, pro7'isio)ially. 



Named in honor of Mr. Wm. H. Bean, of Lebanon Ohio, from whom I received a very 

 fine specimen. 



Locality — Cincinnati and other places in the Cincinnati group. 



Ceramopora (?) irregularis. (James.) Polyzoary incrusting other substances. 

 Cell apertures very irregular in size and shape, some twice as large as others and without 

 any apparant regular arrangement — circular, oval, triangular, and other forms. Cell walls 

 rather thick ; apertures in best preserved specimens oblique, but generally they appear 

 direct. An average of about six cells in the space of a line. The general surface resem- 

 bles somewhat Lhaetetes Jamesi Nicholson, on which it is frequently found grown, and 

 it is sometimes taken tor that species. In some cases it seems to have grown in superim- 

 posed layers. 



Locality — Cincinnati and vicinity, having a vertical range of 500 or 600 feet. 



Ceramopora alternata. (James.) Polyzoary consisting of hollow, branching, 

 cylindrical or compressed stems from one to four lines in diameter, with irregular swell- 

 ings; the hollows filled with foreign matter, (clay). Cell apertures of the most perfect 

 specimens, elevated, oblique, arched, sub-circular or oval ; five or six in the space of a line 

 including the interspaces ; generally arranged in alternating rows, sometimes in a diago- 

 nal manner around the branches. Spaces between the cells equal to their diameter or a 

 little more or less on different examples. Slightly cut longitudinal sections of some speci- 

 mens show the cells arranged in diagonal, alternating rows of a lozenge-shape, with minute 

 interstitial pores. Distributed over the surface about two lines apart, are spots, sometimes 

 slightly elevated, bearing fewer cell apertures and more or less of the small pores. The 

 surface of worn or weathered examples — mostly so found — are nearly smooth ; destitute in 

 most cases of prominent cell mouths, but show more minute interstitial tubes and divi- 

 sions, than perfect specimens. 



Locality — Cincinnati and vicinity. 



Ceramopora eoncentrica. (James.) The parts of the Polyzoary observed consist of 

 cylindrical or flattened branching stems from one-eighth to one-half an inch in diameter, 

 built up of concentric layers, each layer from one-quarter to one-half a line in thickness, 

 and having for a nucleus a crinoidal column or some other foreign substance, in some cases 

 evidently of a perishable nature, which, having decayed, left the stems in a condition to 

 become flattened by pressure. The small cylindrical specimens have only a single layer, 

 about one-half a line in thickness around the central object. On the surface of most 

 specimens are maculae about two lines apart from center to center, occupied liy from 

 three to six cell tubes spreading in diflerent directions at a very low angle. On the 

 general surface the cell apertures are raised and arched in a hooded manner; walls 

 rather thick, and, when most perfect, the raised margins are thin and sharp, when slightly 

 weathered or worn, more or less small interstitial pores are shown. In some cases the 

 cells are arranged in short alternating series. Cell apertures circular or oval, and about 

 five in the space of a line. A slightly cut or ground specimen shows the interior of 

 the cells arranged much like some specimens, so treated, of the preceding, and occasion- 

 ally parts of the surface resemble that species, (C. alternata.) 



