EXPLANATION OF PLATE 1. 



Dendrograptus compactus . 



Page 21. ■? 

 Fig. 1. Frond sliovving the mode of branching-, and its compact character as 

 compared with associated forms. 



Graptolithus annectans. 

 Page 20. 



Fig. 2. A very perfect frond, showing the small radical and the widely bi fur-, 



eating, slender, fiexuous stipes. 

 Fig. 2 a. Enlargement of a portion of the stipe to five diameters to show the 



character of the cellules. 



Sagenella ambigua. 

 Page 22. 



Fig. 3. View of a portion of a frond that is attached to the shell of an Endoceras 

 'proteiforme. 



Fig. 3 a. Enlargement of a portion to show the arrangement of the cells. 

 Mr. E. Hurlburt's collection. 



Dendrograptus tenuiramosus. 

 Page 21. 



Fig. 4. A very perfect frond showing the fiexuous stipe and slender branches. 



Dendrograptus simplex. 

 Page 20. 



Fig. 5. A portion of a frond showing the celluliferous side. 

 Fig. 6. The noncelluliferous side of a frond which differs somewhat in its mode 

 of branching. 



Fig. 5 a. Enlargement of a portion of a branch of fig 5. 



Fig. 5 b. Still further enlargement of a cellule on 5 a to show its character and 

 position on the branch. 



Orthoceras Oneidaense 

 Page 22. 



Fig. 7. Natural size and appearance of the individual described. 

 Fig. 7 a. Enlargement to show the cancellated surface. 



MODIOLOPSIS CANCELLATA. 

 Page 22 



Fig. 8. View of a right valve, natural size. 



Fig. 8 a. Enlargement of the surface. The concentric striaS are not as strongly 

 indicated as they should be. 



