Upper Helderberg Group. 433 



Zaphrektis planima, n. sp. fl3~l*J*§f7*X8, 

 Corallum simple, turbinate, straight; exterior with undulations of 

 growth; height of corallum 60 mm.; diameter of calix 30 mm., depth 

 15 mm., sides nearly vertical, a space at the bottom 15 mm. in diam- 

 eter, flat and smooth ; the fossette consists of a deep depression at the 

 anterior margin of the flat space ; number of lamellae from 85 to 90, 

 of nearly uniform thickness, alternating in length, the principal ones 

 faintly indicated on the outer portion of the flat space, sometimes con- 

 tinuing to the center. In one individual the bottom of the cup is 

 marked by a ridge in continuation of the fossette. 



Formation and locality. Corniferous limestone. Falls of the 

 Ohio. 



Zaphrektis FUSIEORMIS, 11. sp.T}9-l*Ti* C&>* 



Corallum simple, turbinate, very slightly curved, a little com- 

 pressed, upper portion generally constricted ; exterior with slight un- 

 dulations of growth ; height 20 mm., diameter at 10 mm. from the base 

 12 mm.; diameter of the calix 8 mm., depth 5 mm., at the bottom a 

 slightly concave space 3 mm. in diameter; fossette narrow, conspicu- 

 ous, commencing a short distance from the center and continuing to 

 the anterior margin ; number of lamellae 60, alternating in size, the 

 smaller ones. scarcely more than rudimentary, the principal ones ex- 

 tending to the concave space at the bottom of the calix and abruptly 

 ending. This species is easily recognized by its small size, constricted 

 calix arid peculiar appearance of the center. 



Formation and locality. Corniferous limestone. Near Louisville, 

 Kentucky. 



Zaphrektis ovalis, n. sp. 



Corallum simple, turbinate, straight or curved, slightly compressed ; 

 exterior with numerous constrictions caused by intermittent growth ; 

 height 50 mm.; diameter of calix 25 mm,, depth 10 mm., sides nearly 

 vertical, a flat space at the bottom 15 mm. in diameter; fossette con- 

 sisting of a deep depression at the dextral margin of the flattened 

 area at the bottom of the calix ; number of lamellae 75, of uniform 

 size, extending a short distance upon and coalescing with the tabulae, 

 becoming obsolete and leaving a nearly flat smooth space 13 mm. in 

 diameter. It is possible, though not observed in the individuals ex- 

 amined, that at the margin of the cup there are small rudimentary 

 lamellae, in that case the number of lamellae would be double that given 

 above. 



Formation and locality. Corniferous limestone. Falls of the 

 Ohio. 



[Sen. Doc. No. 38.] 55 



