52 KBNTUCK f GEOLOGICAL SURVEY. 



are somewhat irregular in their course, thin walled and Avithout 

 diaphragms in the axial region ; in the mature region they have 

 well-developed, ring-like walls, and diaphragms varying from 

 2 to 3 or 4 in the space of two tube diameters. 



Occurrence : Very abundant in the Mount Hope beds of the 

 Maysville group near Maysville, Ky. Also occurs, but much less 

 abundantly, in the same beds at Cincinnati, Ohio. 



CONSTELLARIA PROMT XENS ULRICH. 



Plate 2. fig. 15. 



Constellaria florida var. promineDs Ulrieh, Jour. Cincinnati Soc. Nat Hist, 

 vol. 6, p. 269, pi. xiv, 3, 1883. 



Zoarium somewhat variable in form, ranging from cylindrical 

 to frondescent, 3 or 4 to 6 mm. in diameter or thickness, and up 

 to 12 or 15 mm. in breadth, and may attain a height of 100 mm. 

 or more. Surface marked by prominent stellate areas, with a 

 more or less regular arrangement in rows, 2 to 2.5 mm. in diam- 

 eter and 3 mm. apart from center to center. These consist of 

 a depressed central space, surrounded by from 5 to 9 prominent 

 and radially arranged, elevated ridges occupied by circular aper- 

 tures, with a small but distinct rim. The depressed portion 

 of the stellate area and the interspaces between the apertures oc- 

 cupied by the very numerous mesopores which may be closed at 

 the surface. Zooecial tubes with thin walls, which are some- 

 what thickened in the peripheral region, and few diaphragms. 

 Mesopores with closely set diaphragms. No acanthapores. 



Occurrence: A common form in the Mount Hope beds in 

 Kentucky and Ohio. It is also found in the upper Eden at New- 

 port and Covington, Ky., and Cincinnati, Ohio. 



AMPLEXOPORA SEPTOSA (ULRICH). 



Plate 3.. fig. 1. 



Atactopora septosa. Ulrieh, Jour. Cincinnati Soc. Nat. Hist, vol. 2, p. 125, 

 pi. xii, 7-7c, 1879. 



Zoarium ramose, from an expanded base attached to various 

 objects, and branching usually at short intervals. Branches 



