Niagara Group. 413 



depth 10 mm.; number of lamellae 50, alternating in size, smaller ones 

 rudimentary ; commencing at the center and continuing to the ante- 

 rior margin is an excessively developed lamella which is prominent at 

 •the center, becoming less so as it approaches the margin, and at nearly 

 right angles to it are two narrow fossettes ; the two lamellae anterior 

 to the fossettes are somewhat more prominent than the others. 

 Formation and locality. Niagara group, Louisville, Kentucky. 



Anisophyllum trifurcatum, n. sp. 



Corallum simple, elongate, turbinate, slender, very gradually en- 

 larging ; exterior with numerous concentric wrinkles and striations ; 

 height 20 mm., diameter of the calix 8 mm., depth 5 mm., number of 

 lamellae 54, three of the lamellae more prominent than the others, one 

 of which is situated anteriorly, the other two laterally, the remainder 

 alternate in size, the smaller ones extending but a short distance from 

 the margin ; some of the lamellae converge to the three prominent 

 ones, the others to the center of the calix. This species may be dis- 

 tinguished from A. unilargum by its somewhat more slender form, 

 its thinner lamellae and the absence of lateral fossettes. The promi- 

 nent lamellae are not excessively developed. 



Formation and locality. Niagara group, Louisville, Kentucky. 



ANISOPHYLLUM ? BILAMELLATUM, n. Sp. 



Corallum simple, turbinate, curved, acute at the base, regularly ex- 

 panding to the calix; exterior with frequent rounded annulations; 

 external costae distinct ; height of corallum 35 mm., diameter of the 

 calix 20 mm., length of anterior side 25 mm.; the bottom of the cup 

 is 4 mm. from the posterior side ; number of lamellae 64. Commenc- 

 ing at the bottom of the calix, and extending to the dextral and sinis- 

 tral margins, are two excessively developed lamellae, the remainder 

 alternate in size, the larger ones extending to the bottom of the calix 



Formation and locality. Niagara group, Louisville, Kentucky. 



ZAPHRENTIS, Rafinesque. 



ZAPHRENTIS RIGIDA, 71. sp. 

 Corallum simple, turbinate, slightly curved, diameter of the calix 

 20 mm., depth 20 mm., sides abruptly descending; a space at the bottom 

 10 mm. in diameter convex ; fossette situated anteriorly, narrow, deep, 

 margins well defined, not extending on the side ; number of lamellae 

 70, of nearly uniform size at the margin, decidedly alternating below, 

 the smaller ones extending to the convex space at the bottom, the 



