REPORT OF THE DIRECTOR I919 121 



fruticosus, Didymograptvis gracilis, D. 

 e 1 1 e s a e and Phyllograptus anna. We will call it 

 the subzone of Goniograptus geometricus and Phyllograptus anna. 



The second subzone (bed s) is characterized by D i d y m o - 

 graptus similis, D. caduceus, Phyllograptus 

 t y p u s and P . anna, besides the dominant D i d y m o - 

 graptus bifidus. This bed shows a strange recurrence 

 of forms, noted much earlier elsewhere, especially in Phyllo- 

 graptus typus (see Point Levis section, p. 120). We will 

 call it the suhhorizon of Didymo graptus similis and Phyllograptus 

 typus. 



Finally, the zone of Diplograptus dentatus also distinctly falls into 

 two subhorizons, namely: 



a That of Phyllograptus angustifolius and Retiograptus tentacu- 

 latus (bed 6) 



h That of Desmograptus, (D. cancellatus, D. intricatus, D. suc- 

 culentus) and Trigonograptus ensiformis. (bed 7) 

 Another common form is Climacograptus anten- 

 na r i u s . 



There occurs, however, at the Ashhill quarry at Mount Moreno 

 near Hudson (see Memoir 7, p. 449) a horizon of the zone of 

 Diplograptus dentatus that is distinctly older than any of the two 

 observed at the Deep Kill. This subhorizon is characterized by the 

 dominancy of Diplograptus dentatus and Climaco- 

 graptus pungens and the frequent occurrence of 

 Ptilograptus plumosus and Didymograptus 

 forcipiformi's, the latter a new species. It may therefore 

 be designated the suhhorizon of Climacograptus pungens and 

 Didymograp tus forcipiformis. 



The complete list of our Deep Kill horizons is then, in ascending 

 order : 



1 Zone of Clonograptus flexilis and Tetragraptus "] r^ . 



2 Zone of Phyllograptus typus and Tetragraptus I v> r1 



quadribrachiatus J 



3 Zone of Didymograptus . "1 



a Subzone of D. nitidus, D. patulus j Didymograptus 



b Subzone of D. extensus, Goniogr. f beds 



thureaui 



4 Zone of Didymograptus bifidus 



a Subzone of Goniogr. geometricus, Phyllogr. anna 

 b Subzone of Didymogr. similis, Phyllogr. typus 



