554 NEW YORK STATE MUSEUM 



direction in which the specimens lie in some beds. But it was 

 always a very gentle flow, as otherwise neither the very fine 

 mud nor the graptolites themselves could have been deposited 

 thus. 



GRAPTOLITE ZONES OF THE DEEP KILL SECTION 



A. Tetragraptus zone 



Graptolite bed no. 1 



The first graptolite fauna of the section occurs in bed d and 

 is characterized by the prevalence of representatives of the 

 genus Didymograptus, notably of Didymograptus pat- 

 u 1 u s, the colonies of which are found in great profusion 

 on every slab from this bed. The entire faunule of bed d con- 

 sists of the following forms: 



1 Callograptus salteri Hall rr 



2 Bryograptus sp. nov. c 



3 Dichograptus octobrachiatus Hall rr 



4 Tetragraptus serra Brong. (=T. bryonoides 



Hall) r 



5 Tetragraptus bigsbyi Hall c 



6 T. fruticosus Hall c 



7 T. sp. nav. r 



8 Didymograptus nitidus Hall < c 



9 D. patulus Hall cc 



10 Phyllograptus ilicifolius Hall r ,; 



11 P. angustifolius Hall rr 



12 Dawsonia monodon Gurley c 



13 Caryocaris sp. c 



14 Small oboloid and linguloid brachiopods cc 



15 Small indet. gastropods r 



Graptolite "bed no. 2 



The next faunule is that of bed f, which is separated from the 

 preceding by only 1 foot 8 inches of barren layers. This grapto- 

 lite bed, with a thickness of 1 foot 9 inches, proved not only 

 extremely rich in number of species and specimens, but specially 

 valuable on account of the excellent state of preservation of 



