5' 2 



NEW YORK STATE MUSEUM 



PLATE 12 

 Genus mastigograptus nov. 



See plates 9-1 1 



Mastigograptus tenuiramosus (Walcott) 



See plate 9, figures 2, 3 ; plate 10, figure 1 ; plate 11, figures 1-4 

 Page 216 



i, 2 Enlargements (x 5) to show the structure of the branches and the 

 apertures of the thecae 



Utica shale, Holland Patent, N. Y. 



Mastigograptus simplex (Walcott) 



See plate 9, figure 1 

 Page 218 



3-5 Enlargements (x 5) showing the structure of the branches and the 

 location of the apertures of the thecae 

 Utica shale, Holland Patent, N. Y. 



Mastigograptus arundinaceus (Hall) 



Page 221 



6 Enlargement (x 5) of type specimen (holotype) 

 Utica shale, Turin, Lewis co., N. Y. 



Mastigograptus circinalis sp. nov. 



See plate 10, figure 3 

 Page 221 



7, 8 Enlargements (x 5) of the types showing the thecal apertures and 

 mode of branching 



Utica shale, Rural cemetery, Albany, N. Y. 



Genus thamnograptus Hall 



Set plate 10 



Thamnograptus capillaris (Emmons) 



See plate 10, figures 4-S 

 Page 206 



9 Fragment of thin branch, showing its composition of thecae. x 5 

 10-12 Fragments ol branches with nodes. x 5 



