STUDY OF THE GRAPTOLITES. 

 Fiff. 12. 



179 



Graptoltthus (Ccenooraptus) divergens. 

 Another form, which we know only in small individuals, is illustrated in 

 the following figures, which remind one of some forms of the recent Genua 



f R,TSIA. ^ 



Fig. 13. Fig. 14. Fig. 16. Fig. 16. 



(These figures are enlarged to twice their natural size.) 

 In another form with similar angular cellules, we have the following 

 illustrations of the mode of occurrence of the species. 



Fig. 17. 



Graptolithus (C(EN0GRAPTUS) qbacilis. 



* Should this form prove not to be the young of O. gracilis, it will require a new desig- 

 nation for which the specific name of surcularis will be appropriate, while the entire group 

 will require to be separated under a distinct generic or sub-generio head, for which I pro- 

 pose the name Cc&nograptus, 



