GUAl'TOLITES OF NEW YORK. I'ART 1 /<o 



Didymograptus nicholsoni Lapwoith, var. planus Elles & Wood 



Page 685 



10 Imperfect specimen ^vith slightly reclined branches in the compressed state. 



Reverse side. x2 



11 Typical rhabdosome. xll 



1*2 Yoiino; rhabdosome. Obverse side. x2 



13 Specimen showing distinctly the origin of first theca. x2 



14 Same in natnral size 



Graptolite bed 2 of the Deep kill section 



Didymograptus acutidens Lapworth 



Page 683 



15 Characteristic rhabdosome. xly^ 



Graptolite bed 2 of the Deep kill section 



Didymograptus cuspidatus sp. nov. 



Page 684 



16 Sole rhabdosome observed 



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



Didymograptus extensus Hall (sp.j 



Page 668 

 _ , _ See pi. 14 



17, 1(5 Constrictiform appearance 



Graptolite bed 2 of the Deep kill section 



