546 NEW YORK STATE MUSEUM 



PLATE 23 



Genus cryptograptus Lapworth 

 Cryptograptus tricornis (Carruthers) 



Page 443 



1 Group of specimens showing- the common aspect of the form 



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



2 Frontal view of rhabdosome, showing also character of sicular extremity. 



Too wide in reproduction 



3 Large specimen with long nemacaulus 



4 Specimen with inflation of nemacaulus 



Normanskill shale, Glenmont, N. Y. 



Cryptograptus tricornis mut. insectiformis nov. 



Page 448 



5 Portion of slab with group of specimens showing the typical aspect of 



the mutation (cotypes) 



Lowest Utica shale, Van Schaick island, Cohoes, N. Y. 



Genus climacograptus Hall 

 Climacograptus typicalis Hall 



Page 407 



6 Large typical specimen 



Utica shale, Holland Patent, N. Y. 



7 A narrow variety 



Utica shale, Lees Gulf, Lewis co., N. Y. 



Climacograptus typicalis mut. spinifer nov. 



Page 411 



8 Original of Pal. N. Y. v. 1, pi. 72, fig. 2a, 2b, redrawn (cotype) 



Utica shale, Ballston, N. Y. 



9 Typical rhabdosome (cotype) 



Transition shale, Sandy Hill, N. Y. 



