Maryland Geological Survey 205 



Cyatkophyllum ixequale (Hall) 

 Plate XX, Figs. 1-4 



Columnaria inequalis Hall, 1882, Pal. N. Y., vol. ii, p. 323, pi. Ixxii, figs. 3a, b, 



4a-4c. 

 Acervularia ? inequalis Hall and Whitfield, 1873, 23d Rept. N. Y. State Mus. 



Nat. Hist., p. 233. 

 Acervularia communis Simpson, 1889, Trans. Amer. Philos. Soc, vol. xvi, 



p. 459, and text fig. 

 Prismatophyllum inequalis Weller, 1903, Pal. N. J., vol. iii, p. 219, pi. xvii, 



figs. 12, 13. 



Description. — Coralluni compound, composed of closely united polygo- 

 nal corallites, which radiate from a common center and increase by in- 

 terstitial gemmation. Corallites unequal in size, larger individuals 4 to 

 6 mm. diameter. External walls appear somewhat zigzag in cross-sections. 

 Septa about 30 to 3G in -large individuals. Primary septa unequal in 

 length, some reaching center. Secondary septa a little shorter. Septa are 

 not flat but appear as undulating lines in transverse sections. Cross- 

 sections show an outer zone of vesicles occupying about i diameter of 

 corallite, the width of zone being about one-half length of primary septa ; 

 septa carinate in central part which is without vesicles. Longitudinal 

 sections show vesicles to be elongate, their longer diameter being directed 

 upwards and outwards; vesicles curved, their convex side directed upward 

 and outward. 



Diameter of largest specimen observed, 110 mm. Corallites diameter, 

 4 to 6 mm. 



This species resembles C. mgosuiii from which it ditfers in much smaller 

 size of corallites, fewer septa, inequality of length of primary septa, and 

 no observed tendency of corallites to break apart. It resembles some 

 species of Acervularia but does not have apparent inner wall of that genus. 

 It occurs abundantly in the Cladopur/i rcctilineata zone of the Decker 

 Ferry of Xew Jersey. In ^Maryland it is found in the Cladopora recti- 

 lineata zone near base of Keyser and according to Ulrich in the Keyser 

 coral zone. 



Occurrence. — Heldekbeko Fokmation, Keyser Member. Martin 

 Mountain, Allegany County. 



Collection. — Maryland Geological Survey. 



