522 NEW YORK STATE MUSEUM 



PLATE 17 



Nemagraptus gracilis var. surcularis (Hall) 



Page 282 



i Specimen from the type locality (topotype) 



2 Typical specimen 



Normanskill shale, Kenwood, N. Y. 



Nemagraptus exilis Lapworth 



Page 287 



3 Typical specimen showing length of branches and sicula 



Normanskill shale, Glenmont, N. Y. 



4 Young specimen showing lateral spines. From type locality (topotype) 



Normanskill shale, Stockport, N. Y. 



5 More robust form 



Normanskill shale, Glenmont, N. Y. 



6 Young individual without secondary branches 



Normanskill shale, Stockport, N. Y. 



7 Specimen possessing more than usual number of secondary branches 



Normanskill shale, Stockport, N. Y. 

 8,9 Slender forms with few secondary branches, growing only far from 

 center of rhabdosome 

 Normanskill shale, Glenmont, N. Y. 



Nemagraptus exilis var. linearis no v. 



Page 290 



10 Typical specimen (cotype) 



Normanskill shale, Speigletown near Trow N. Y. 



1 1 Typical specimen (cotype) 



[2 Group of specimens, showing secondary brandies (cotypes) 

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



