177. CONTRIBUTION TO 



Found in the Upper Devonian (Hamilton group) at Charlestown and at the 

 different cement quarries throughout Clark county, Indiana. Now in the col- 

 lection of the author. 



ZAPHRENTIS ALBACORNIS, N. Sp. 



Plate 52. Figs. 6, 7. 



Corallum, simple, turbinate, straight or regularly curved. Acute at the 

 point of attachment. Rapidly expanding in diameter to the calix. Height 

 from thirty to G.hy millimeters. Calix oblique, broadly campanulate, thirty 

 millimeters in diameter. Depth twenty millimeters. Number of lamellae one 

 hundred, in the circumference of a calix thirty millimeters in diameter, some- 

 what rounded and slightly unequal in size at the margin, alternating below, 

 gradually sloping to the bottom of the calix, where the short ones gradually 

 terminate, the longer ones continue to within two millimeters of the center of 

 the calix and abruptly end, leaving a smooth, convex space in the bottom of the 

 calix, four millimeters in diameter. Exterior comparatively smooth, a few 

 shallow, distant annulations and wrinkles, caused by intermittent growth. 

 Fossette consists of a shallow depression at the anterior margin of the convex 

 space in the bottom of the cup, but does not extend on the side of the calix. 



Found in the Upper Devonian (Hamilton group) at Charlestown, and at 

 the different cement quarries in Clark county, Indiana. Now in the collection 

 of the author. 



ZAPHRENTIS COMPRESSA. Milne Edwards. 



Plate 52. Figs. 8, 9, 10, 11. 



Zaphrentis Compressa, Milne Edwards, HistoireNaturelle Des Coralliaires, page 342, plate 

 61, figures 3 a, 3 b, 1860. 



Zaphrentis laneeolata, Worthen, Greological Survey of Illinois, Volume VIII, page 76, 

 plate 10, figures 4, 4 a, 4 b, 1890. 



Worthen's Description : Corallum small, pointed at the lower extremity, 

 compressed, lanceolate widening regularly from the pointed extremity to the 

 upper margin of the cup. Septal fossette well developed and ranged in direc- 

 tion with the greatest diameter of the cup. Lamellae twenty- two to twenty- 

 four, all reaching to the border of the septal fossette. 



Length of an average size specimen 13-16 inch; breadth across the great- 

 est diameter of the cup 6-16 inch. The broadest specimen seen measured in 

 length 10 16 inch, breadth of cup across its greatest diameter 9-16 inch, in the 

 opposite direction 5-16. 



