PLATE Y. 
Favosites Helderbergi^e. 
Page 8. 
See Plates 4, 6. 
Fig. 1. An elongate subturbinate form, showing larger cells at intervals, most of which are filled with 
siliceous matter. 
Lower Helderberg group. Clarksville, N. Y. 
Fig. 2. A broad, turbinate form of the species. 
Lower Helderberg group. Clarksville, N. Y. 
Fig. 3. A depressed, hemispheric form where the vertical extent is about one-fifth or one-sixth of the 
diameter. The figure represents the convex upper side of the specimen, fig. 2, plate 4, which 
is the prevailing form in many localities. 
Lower Helderberg group. Clarksville, N. Y. 
