496 NEW YORK STATE MUSEUM 



PLATE 4 



Genus desmoqraptus Hopkinson 



See plates 1, 5 



Desmograptus cadens (Hall) 



Page 180 



1 Type specimen (holotype ?) 



Hamilton shale, Moscow, N. Y. 



Genus dictyonema Hall 



.SV^ plates 1-3, 5 



Dictyonema areyi Gurley 



Page 164 



2 Type specimen (cotype) 



Rochester shale, Rochester, N. Y. 



Dictyonema perradiatum Gurley 



Page 168 



3 Type specimen (holotype) 



Onondaga limestone, Leroy, N. Y. 



Dictyonema hamiltoniae Hall 



Page 169 



4 A labeled specimen of the Hall collection (cotype ?) 



Hamilton shale, Moscow, N. Y. 



All figures are drawn in natural size ; the originals of figures i and 4 

 are in the American Museum of Natural History ; that of figure 2 

 is in the collection of Prof. A. L. Arey, Brooklyn, N. Y. ami 

 that of figure 3 is in the National Museum. 



