GRAPTOLITES OF NEW YORK, PART 1 775 



Didymograptus gracilis Tornquist 



Page 679 



15, 16 Mature rhabdosomes 



17 Obverse side of rliabdosorae. x2 



Graptolite bed 8 of the Deep kill section 



18 Relatively large specimen 



Ash hill qiiarr}', Mt Moreno, Columbia co. N. Y. 



19 Distal portion of branch with extremely slender thecae. x6^ 



20 Another similar fragment. x8 



21 Enlargement (x8) of proximal portion of rhabdosome, to show sicula and 



proximal thecae 

 Graptolite bed 8 of the Deep kill section 



Didymograptus ellesi sp. nov. 



Page 683 



22, 28 Typical rhabdosomes 



24 Rhabdosome. x2 



Graptolite bed 3 of the Deep kill section 



Didymograptus similis Hall (sp.) 



Page 677 



25 Typical specimen 



Graptolite bed 3 of the Deep kill section 



26 Proximal portion of rhabdosome 



Ash hill quarry, Mt Moreno, Columbia co. N. Y. 



27 Fragment of large rhabdosome, referred to this species 



28 Proximal portion of rliabdosorae. Obverse side. x2 



29 Young rhabdosome. x2 



Graptolite bed 8 of Deep kill section 



Didymograptus spinosus sp. nov. 



Page 688 



30 Largest specimen observed 



31 Enlargement (x5) of proximal portion to show sicula, thecae and 



spines 



32 Young rhabdosome 



Ash hill quarry, Mt Moreno, Columbia co. N. Y. 



