14 PALEONTOLOGY OF NEW YORK. 



ChjETETES (MoNOTRYPELLA) DEN80S. 



PLATE X, FIGS. U-IS. 



TremaUtpora deiua. Hall. Tweiity-mxth Kept. N. Y. $Ut« Mus. Nat. Hist., p. 105. 1874. 

 Trrmainptfra {Chatties) rfoMO, Hall. Thirty-secimd Kept N. Y. State Mus. Nat. Hist., p. 150. 1S79. 



Hepoi-t of State Geologist for 1882. Expl. pi. 10, figs. 11-13. 1883. 



CoRALLUM ramose, solid ; diameter of branches from 3 to 4 mm. Cells tubular, 

 polygonal, arising from the center of the branch and quite regularly curving 

 to the surface ; diameter at the apertures somewhat variable, but generally 

 about .33 mm. ; walls thin, sometimes becoming much thickened at the sur- 

 face, constricting the apertures ; frequently spinulose at the angles. Septa 

 thin, occurring only near the surface. Surface marked by occasional 

 maculaB, where the cells are larger than on other portions, having a 

 diameter of .50 mm. 



Formation and localities. In the shaly limestone of the Lower Helderberg 

 group, at Catskill creek, and near Clarksville, N. Y. 



PTYCHONEMA, N. G. 



Pttchonema, n. s. g. 

 Distinguished by the strong corrugations of the cell walls and absence of septa. 



Ch.«!tete8 (Ptychonema) tabulatus. 



PLATE IX, FIG8. 12-15. 



CStmUUatalmlatui, Haii. Illustrations of Devonian Fossils, Corals : PI. 37, figs. 16-19. 1876. 

 •* " " Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 149. 1879. 



" f " " Report of State Geologist for 1882. Expl. pl. 9, figs. 12-15. 1883. 



CoRALLDM forming spheroidal or hemispheric masses. Diameter of the largest 

 specimen observed 45 mm. Cell tubes polygonal, arising from the center of 

 the base and incresising by interstitial additions. Diameter at the aperture 

 about .50 mm. ; walls thin, very strongly and regularly corrugated, the cor- 

 rugations forming nodes at the angles ; about fifteen corrugations in the space 

 of 5 mm. Septa, so far as observed, wanting. 



Formation and locality. Probably from the Upper Helderberg group, Scho- 

 harie, N. Y. 



