GKAPTOLITES OF NEW YORK, PART 1 



751 



12 Young rhabdosome with branches of a higher order 



13 Still more advanced rhabdosome 



14 Specimen in the mature condition 



15 Lateral view of a portion of a mature branch. x4i 



16 Fragment of a colony exhibiting an undulating character of the 



branches 



17 A laterally compressed early growth stage, giving a lateral view of the 



early thecae and the bryograptoid aspect of the young colony. x5 



18 The same view of a more advanced growth stage. x5 



19 The bryograptoid aspect of an adolescent stage. x5 



20 The same aspect of a young, dense form 



Staurograptus dichotomus var. apertus var. nov. 



21 The bryograptoid aspect of a mature, loosely branched form with few 



bifurcations 



22 A variety Avith extreme scarcity of branching 



23 A mature specimen with moderately scarce branching and widely diverg- 



ing bi-anches 



24 A specimen Avith extremely widely divergent branches and scarce 



bifurcation 

 All specimens are from the upper Cambric shales at Schaghticoke, 

 Rensselaer co. N. Y. The originals are in the New York State 

 Museum. 



