FIG. 



GUELPH FAUNA IN THE STATE OF NEW YORK 141 



Clathrodictyum ostiolatum Nicholson 



10 Surface view of specimen, showing the characteristic botryoidal 



surface. Natural size 

 1 1 Section, shown on broken side of same specimen, and exhibit- 



ing the calcareous laminae. Natural size 



12 Thin section of a portion, X2, showing the laminae and inter- 



mediate vertical dissepiments 



Stromatopora galtensis Dawson (sp.) 



Page 36 



13 A fragment exhibiting the astrorhizae. X3 



The originals of fig. 1-5, 10-13 are from the Guelph bed at 

 Rochester (Arey collection) ; those of fig. 6-9 from the Upper 

 Shelby bed (N. Y. State Museum). 



