270 S. WELLER FAUNA OF THE FERN GLEN FORMATION 



diameter very gradually. Epitheca thin, without spinous outgrowths of 

 any kind, marked by low, broad, more or less indistinct longitudinal 

 costse which correspond in position with the septa; also by fine annular 

 striae and by more or less inconspicuous annular wrinkles. Calyx of 

 moderate depth, septa 34 or 36 in number, which, as seen in polished 

 sections, are arranged in pairs. The central axis of the corallum occu- 

 pied by a strong columella, which is prominently extended upward in the 

 bottom of the calyx. Dissepiments few, curving upward in passing from 

 the outer wall to the columella. 



The dimensions of a large individual are: Length along the convex 

 side, 36 millimeters; diameter at rim of calyx, 7 millimeters. 



Remarks. — This species differs from C. cynodon E. & C, as described 

 by Milne-Edwards and Hainie, from the lower Mississippian strata in the 

 hills south of Louisville, Kentucky, in the absence of the longitudinal 

 series of fine spines upon the epitheca, in the greater curvature of the 

 corallum, and in the shorter and blunter extension of the columella in 

 the calyx. 



As compared with C. tantilla (S. A. M.), 4 from the Chouteau lime- 

 stone of central Missouri, the species is much larger, more curved, with 

 a larger number of septa, and with comparatively fainter longitudinal 

 costse. 



Occasionally an individual among these Fern Glen specimens occurs 

 with what seem to be one or more strong, spine-like growths from the 

 epitheca, but close observation shows these bodies to be not a part of the 

 coral itself, but parasitic growths upon the coral, many or all of them 

 being the bases of attachment of bryozoan colonies. 



CYATIIAXONIA MINOR n. sp. 



Plate 10, figures 14-17 



Description. — Corallum small, slender, curved or sometimes nearlv 

 straight, pointed below, tapering very gradually above, the upper half 

 sometimes not increasing at all in diameter. Epitheca thin, without 

 spines or tubercles, the surface marked by faint, longitudinal costae 

 which correspond in number with the septa; also by fine annular stria? 

 which can only be detected with a magnifying glass, and by more or less 

 inconspicuous annular wrinkles. Calyx of moderate depth, septa 26 to 20 

 in number. The central axis of the corallum occupied by a rather strong 

 columella, which is extended upward in the bottom of the calyx. 



4 Zaphrentis tantilla S. A. M. ; Seventeenth Report of the Geological Survey of Indi- 

 ana, p. 621, pi. 1, figs. 23-24. 



