INDIANA PALEONTOLOGY. 23. 



ZAPHRENTIS HOBBSI, N. Sp. 



Plate 8, Figs. 4-5-6. 



Corallum simple, elongate turbinate, or conico cylindrical. Acute at the 

 base, or jn some examples there is a broad scar at the base of attachment. Grad- 

 ually increasing in diameter to the calix, in some examples, the diameter is es- 

 sentially the same throughout. Calix with thin vertical walls, twenty millime- 

 ters in diameter. Depth twenty to thirty millimeters. Tabulse flat, occupies 

 the entire diameter of the corallum. Number of lamellte seventy to eighty, 

 rounded and equal in size at the margin, alternating below, the short ones be- 

 coming thinner as they approach the bottom of the calix. but disappear before 

 reaching the tabulae, the longer ones are slightly elevated, and thinner, and con- 

 tinue to the tabulge, and abruptly terminate, leaving the tabulae smooth, and con- 

 vex, slightly less than the diameter of the corallum. Exterior with smooth round- 

 ed annulations at somewhat regular intervals, and occasionally, a few shallow 

 wrinkles, caused by intermittent growth. Fossette consists of a slight depres- 

 sion at the margin of the tabulae; position variable. 



The regular annulations, broad flat tabulae, thin vertical walls, and deep 

 calix, makes this easily recognized from all other species. 



Found in the middle Devonian (upper Helderberg group), at the Falls of 

 the Ohio. Now in the collection of the author, 



CLADOPORA GURLEYI, N. Sp. 



Plate 9, Fm. 1. 



Undose laminar expansions. With a central or sub-central attachment. 

 Composed of slightly flattened radiating tubules, intimately joined at their mar- 

 gins. Forming a thin wrinkled epithecal crust, covering the entire under sur- 

 face. Tubes near the base comparitively small, gradually expanding and be- 

 coming more flattened as they approach the surface, and open in oblique oblong 

 orifices, from two to three millimeters wide, and from one to two millimeters in 

 height. Tube walls rather thick. Pores large, not very numerous ; one, very 

 rarely two rows in a tube. Tabula, not very well pronounced, faint traces 

 can be observed in some tubes near the margin. 



The thin undose expansion, the large dilated orifices, and thick walls, and 

 large pores, makes this easily recognized from all other species. 



The specific name is in honor of Prof. Wm .F. E. Gurley, Ex-State Geolo- 

 gist of Illinois, an ardent collector, and a good Palaeontologist. 



Found in the lower Devonian (Corniferous group), at the Falls of the Ohio. 

 Now in the collection of the author. 



