414 Thirty-fifth Keport o$ the State Museum. 



others to the center, where they are twisted, not elevated. The calix 

 of this species most nearly resembles that of S? {Zf) limitare but is 

 proportionally deeper, the lamellae are more decidedly alternating in 

 size and are twisted at the center. The sides are more nearly equal. 

 Formation and locality. Niagara limestone, Racine, Wisconsin. 



Zaphrentis cristulatum, 'n. sp. 



Oorallum simple, turbinate, curved; diameter of the calix 30 mm., 

 depth 20 mm., sides parallel with the exterior of the corallum ; a space 

 at the bottom 15 mm. in diameter slightly convex ; fossette consisting 

 of a deep depression situated anteriorly, not extending on the side of 

 the calix ; number of lamellae from 90 to 100, decidedly alternating in 

 size, the smaller ones about one-fourth the thickness of the others, 

 which fasciculate, coalesce and extend to the center, where they are 

 elevated, forming an elongate crest about 6 mm. in height, in a line 

 with the fossette. 



Formation and locality. Niagara limestone, Racine, Wisconsin. 



Zaphrektis pressula, n. sp. 



Corallum simple, turbinate, curved, compressed ; calix oval, length 

 50 mm., width 35 mm., depth 30 mm.; fossette dextral, narrow, deep, 

 not extending on the side of the cup ; a space at bottom of calix 30 

 mm. in length and 25 mm. in width slightly convex ; number of lam- 

 ellse about 120, of nearly uniform size at the margin, decidedly alter- 

 nating below ; the principal lamellse fasciculate and coalesce, a few 

 extending to the center, where they appear as interrupted contorted 

 ridges. 



Formation and locality. Niagara limestone, St. Charles, Illinois. 



Zaphrentis latisinus, n. sp. 



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

 panding to the calix ; length of posterior side 20 mm., of anterior side 

 50 mm., calix broadly oval, length 45 mm., width 35 mm.; tabulae 

 broad, extending the entire diameter of the corallum ; fossette com- 

 mencing 8 mm. from the center and continuing to the anterior mar- 

 gin, deep and very conspicuous, width 10 mm.; a smooth, slightly 

 depressed space, of the same width as the fossette, continues to the cen- 

 ter ; number of lamellae 40, of uniform size, extending to the smooth 

 space at the bottom of the calix. 



Formation and locality. Niagara limestone, Drummond's Island. 



Zaphrentis subvesiculare, n. sp. 

 Corallum simple, elongate, turbinate, tortuous, acute at the base, 

 quite regularly expanding to the calix, exterior with concentric 



