GRAPTOLITES OF NEW YORK, TART 2 55 1 



Genus retiolites Barrande 



See iilate 31 



Retiolites geinitzianus Barrande var. venosus (Hall) 



See plate 31, fi gurcs 6-8 

 Page 469 



7 Pyritized specimen, showing the original form of the rhabdosome 



Clinton shale, Genesee gorge, Rochester, N. Y. 



8 Compressed and split specimen, showing one of the axes and the 



peridermal ledges 



Clinton shale, Palmer's glen, Rochester, N. Y. 



Genus lasiograptus Lapworth 



See plates 30, 31 



Lasiograptus mucronatus (Hall) 



Set: plate 30, figures 1-5; plate 31, figures 1-3 

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9-1 1 Synrhabdosomes showing the common habitus and dimensions of 

 the rhabdosomes 



Normanskill shale, Glenmont, N. Y. 



Lasiograptus bimucronatus Nicholson 



See plate 30, figures 6-3 ; place 31, figure 4 

 Page 481 



12 Large complete rhabdosome 



13 Smaller specimen, showing the common aspect of the form 



14 Specimen retaining the extrathecal fibers and traces of periderm 



Normanskill shale, Mt Moreno near Hudson, N. Y. 



1 5 Specimen showing the connection of fibers and nemacaulus 



16 Hall's original of decade 2, plate 28, figure 16 redrawn 



Normanskill shale, Kenwood near Albany, N. Y. 



17 Specimen showing straight rigid fibers and inflation of nemacaulus 



18 Specimen with very long extrathecal fibers 



Normanskill shale, Mt Moreno near Hudson, N. Y. 



