29. CONTRIBUTION TO 



five millimeters in diameter. Depth five to ten millimeters, varying in different 

 individuals. A flat convex space in the bottom of the calix, occupied by the 

 tabulffi from five to ten millimeters in diameter. Number of lamella?, eighty in 

 the circumference of a calix, twenty-five millimeters in diameter, rounded and 

 equal in size at the margin, alternating below, from five to ten millimeters from 

 the margin flat, or slightly oval, then abruptly slope to the bottom of the calix,. 

 where they coalesce, and continue to the center of the calix, fasciculating, and 

 twisting, but not elevated. In the example Fig. No. 5, the lamellae does not 

 coalesce, but the short ones, on reaching the bottom of the cup, abruptly end ; 

 the longer ones, continue slightly elevated, and near the center of the calix they 

 coalesce with the adjacent ones, and terminate, not elevated. No fossette. The 

 exterior is somewhat rugged with strong rough wrinkles and deep constrictions, 

 caused by periodical growth. 



The specific name is in honor of Mr. A. C. Benedict, of Indianapolis, In- 

 diana. 



Found in the Niagara group (upper Silurian) at the Beargrass creek quar- 

 ries, near Louisville, Kentucky. Now in the collection of the author. 



' CYSTIPHYLLUM LAMELLATUM, N. Sp. 



Plate 10. Figs. 4-5. 



Corallum simple, turbinate or elongate turbinate, straight or regularly 

 curved. Acute at the base of attachmedt. Gradually or rapidly increasing in 

 diameter to the calix. Exterior rather rugged, with coarse, irregular annula- 

 tions and constrictions, caused by intermittent growth. When decorticated they 

 have the appearance of thin, invaginated cups. Height varying in different 

 individnals from one to six inches or more. Calix somewhat bell-shaped, from 

 fifteen to thirty uiillimeters in diameter. Depth twenty to thirty millimeters, 

 with a concave space in the bottom of the calix, occupied by large cysts, from 

 ten to fifteen millimeters in diameter. Number of septa one hundred in a calix 

 twenty-five millimeters in diameter. Somewhat irregular in -size. Abruptly 

 slope to the edge of the concave area in the bottom of the calix, and terminate.. 

 The exterior shows numerous small <*ysts, not more than ene-third to one-half 

 as large as those situated in the bottom of the calix. 



The concave bottom of the calix, covered with large cysts, the conspicuous 

 septa free from cy^^t^i, and the small cysts on the exterior, with the appearance 

 of thin invaginated cu))S, makes this easily recognized from all other species. 



Found in the upper Devonian (Hamilton group), two miles northwest of 

 Charlestown, Indiana. Now in the collection of the author. ' 



