436 Thirty-fifth Keport on the State Museum. 



alternation being more distinct on the sides than near the margin, 

 where they are thickened and rounded, becoming thin as they approach 

 the center; the adjacent principal lamellae fasciculate, the lamellae 

 thus formed, again fasciculating, coalescing and extending to the cen- 

 ter, where they are slightly twisted. The tabulae are elevated at the 

 center as in the genus Clisiophyllum, but as all the other characters 

 are those of Zaphrentis the mere elevation of the center of the tab- 

 ulae could make no generic difference. 

 Formation and locality. Oorniferous limestone, Falls of the Ohio. 



Zaphrehtis duplicata, n. sp. 



Oorallum simple, turbinate, attenuate below, straight or slightly 

 curved, exterior with low rounded ridges of growth; external 

 striae fine, distinct ; height of corallum 45 mm. ; diameter of the calix 

 30 mm., depth 15 mm., sides nearly vertical, a flat space at the bot- 

 tom 20 mm. in diameter ; f ossette deep, narrow, commencing near the 

 center and extending to the anterior margin; number of lamellce 110 

 near the margin of the cup thickened and rounded, all the lamellae 

 extending a short distance on the flattened space at the bottom ; alter- 

 nate lamellae coalesce with the others, the lamellae thus formed fascic- 

 ulate and coalesce, continuing to the center, where they appear as 

 low tortuous ridges ; the tabulae at the center are elevated, the outer 

 portion bending downwards. This species can be distinguished from 

 Z. frequentata by its finer lamellae, which are thickened and coalescing 

 at the center, and the narrow fossette. 



Formation and locality. Oorniferous limestone, Falls of the Ohio. 



Zaphrentis sentosa, n. sp. 



Corallum simple, elongate turbinate or sub-cylindrical, very grad- 

 ually increasing in diameter; fragments occur 30 mm. long of a nearly 

 uniform diameter of 10 mm.; exterior with fine, distinct, rounded, 

 concentric striae and annulations, at quite regular distances apart; 

 external striae broad, prominent, each representing two lamellae : on the 

 annulations, corresponding in number to the longitudinal striae, are 

 curved spines,turning upwards; having at the base a diameter of 75 mm., 

 length 3 mm., 4 or 5 in the space of 5 mm. Though there are numer- 

 ous specimens of this species no perfect calix has yet been observed. 

 This species may be distinguished from Z. nodulosa as follows : The 

 spinules or conical nodes of that species occur only near the base, the 

 ordinary forms expand quite rapidly, while in this species the increase 

 in diameter is very gradual, the spines are more prominent and ex- 

 tend the whole length of the corallum. 



Formation and locality. Oorniferous limestone, Canada "West. 



