43. CONTRIBUTION TO 



but does not extend on the side of the calix. Exterior, with deep constrictions, 

 and wrinkles, caused by periodical growth. 



The thin numerous lamellea}, and the broad deep fossette ; with the small 

 depressions in the lateral gaps, 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. 



ZAPHRENTIS INFLEXUS. N. Sp. 



Plate 16. Figs. 15-16. 



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

 base of attachment, rapidly expanding in diameter to the calix. Height forty 

 millimeters. Calix broadly campanulate thirty millimeters in diameter. Depth 

 twenty millimeters, a convex space in the bottom of the calix, occupied by the 

 tabulae, ten millimeters in diameter. Number of lamelUo, eighty, rounded and 

 slightly unequal in size at the margin, alternating below, gradually sloping to 

 the bottom of the calix, where the short ones terminate, the longer ones con- 

 tinues to the bottom of the calix, coalescing, and slightly twisting, but not 

 elevated, giving to the lamellae in the bottom of the calix, a zig zag appearance. 

 Fossette, consists of a deep depression, on the posterior side of the tabulae, 

 but does not extend on the side of the calix. 



The manner of coalescing of the lamellae and the zig zag appearance in 

 the bottom of the calix, makes this easily recognized from all other species. 



Found in the middle Devonian (upper Helderberg group) Falls of the Ohio. 

 Now in the collection of the author. 



ZAPHRENTIS PUSILLUS. N. Sp. 



Plate 16. Figs. 17-18-19. 



Corallum simple, rather small, turbinate, straight or slightly curved. A 

 small scar at the base of attachment. Rapidly expanding in diameter to the 

 calix. Height varying in different individuals, from twenty to thirty millime- 

 ters. Calix broad, from ten to thirty millimeters, in diameter. Depth ten mil- 

 limeters. Exterior somewhat rough, with shallow annulations, and wrinkles, 

 caused by intermittent growth, longitudinal striae conspicuous, fourteen in the 

 space of ten millimeters, number of lamellae, ninety-four, in the circumference 

 of a calix twenty-five millimeters in diameter, unequal in size at the margin, 

 the short ones merely rudementary, the longer ones gradually slope to near the 



