764 NEW YORK STATE MUSEUM 



PLATE 9 



Grenus dichograptus Salter 



Dichograptus octobrachiatus Hall (sp.) 



Page 634 

 See pi. 8 



1 Fragmentary rhabdosoraes with mature disks 



Graptolite bed 3 of the Deep kill section 



2 Branch showing the thecae in their lateral aspect 



G-raptolite bed 2 of the Deep kill section 



Grenus loganograptus Hall 

 Loganograptus logani Hall 



Page 631 



3 Young rhabdosome ; its branches drawn too thick 



4 Older rhabdosome 



5 Rhabdosome with extremely tenuous branches 



6 Central portion of a rhabdosome 



All the originals are from graptolite bed 7 of the Deep kill section 



Genus tetragraptus Salter 



See pi. 10, 11, 13 



Tetragraptus (Etagraptus) lentus subgen. nov. et spec. nov. 



Page 666 



7 Rhabdosome 



8 The same enlarged to show the character of the sicula and thecae. x2 



9 Another rhabdosome. xG^ 

 10 Dorsal view of a theca. x6^ 



Graptolite bed 3 of the Deep kill section 



