KENTUCKY GEOLOGICAL SURVEY. 47 



Occurrence : A very common form throughout the Eden in 

 Ohio and Kentucky. It also ranges well up into the Mount 

 Hope beds of the Maysville group. The examples studied by 

 sections were collected in the vicinity of Cincinnati, Ohio. 



AMPLEXOPORA PERSIMILIS N. SP. 



Plate 2, figa. 2, 3. 



Zoarium ramose, branching at variable intervals, usually by 

 bifurcation. Branches from 4 to 15 mm. in diameter, often 

 somewhat flattened. Surface smooth except for the low rounded 

 monticules, which occasionally become conspicuous. Apertures 

 \\ ith thin interspaces, polygonal, indented by the very numerous 

 small acanthopores when the zoarium is in a fine state of preser- 

 vation, 7 or 8 in 2 mm. ; those in the monticules a little larger 

 than the others. Zocecia thin-walled in the immature region, 

 with rather thin distant diaphragms; in the mature region the 

 walls are but little thickened and the zooecia continue to be 

 prismatic. In this region diaphragms vary in their distance 

 apart, ranging from 1 to 3 in the space of a tube diameter. 



The description given above applies to what is considered the 

 typical form. The species is exceedingly abundant and shows 

 a great deal of variation, more especially in the size and number 

 of the acanthopores, and size of zoarium, which may be several 

 times' as large as the dimensions given above indicate. There 

 is also some variation in the size of the' "apertures. 



Occurrence : Very abundant in the lower two-thirds of the 

 Eden group at Cincinnati, Ohio, Covington and Newport, Ky. 

 The typical form was collected from the lower Eden in the west 

 part, of Covington near the bank of the Ohio river. 



DEKAYELLA ULRICHI (NICHOLSON). 



Plate 2, fig. 4. 

 Chsetetes Fletcher!. Nicholson, Paleontology of Ohio, vol. 2, p. 197, pi. xxi, 



7, 7a, 1875. 

 Monti culipora (Heterotrypa) Ulrichii. Nicholson, Genus Monticulipora, p. 



131, fig. 22, 1881. 

 Dekayella ulriohi. Ulrich, Jour. Cincinnati Soc. Nat. Hist., vol. 6, pp. 91, 



153, 1883. 



