GRAPTOLITES OF NEW YORK, PART 1 495 



Clonograpti, which is either not exposed or not represented at the Deep kill. 

 On the other hand, the upper Cambric synthetic genus Bryograptus extends 

 with two species into this horizon, thereby indicating the proximity of the 

 latter to the beginning of the graptolite reign. 



Of Dendroidea we find the genera Dictyonema, Dendrograptus and 

 Callograptus represented in this zone. Finally, the species of Dawsonia 

 and Caryocaris, described in this paper, were also obtained from the same. 



The correlation of this zone with the divisions recognized in Canada and 

 Europe has been fully discussed before [1902]. For this reason only a short 

 summary is here given. 



The Tetragraptus zone of the Deep kill is homotaxial to a part (probably 

 upper part) of the beds termed by Gurley the " Main Point Levis zone " of 

 the Quebec beds. This is the zone containing the typical Quebec graptolite 

 fauna. The same zone is probably present at St John N. B. [Matthew], and 

 at Cow Head, Newfoundland [Billings]. The association of forms, character- 

 istic of this horizon, is typically developed in the Middle Skiddaw slates of 

 the Lake district, north England [Elles]. The Dichograptus bed, which there 

 separates the lower and upper Tetragraptus bed, is probably the exact 

 equivalent of the zone here considered. The more common species of the 

 Tetragraptus zone are also found in the Arenig shales of St Davids, Wales, 

 of the Shelve district in Shropshire, west England, and in the Ballantrae 

 terrane in south Scotland. In Sweden [Tornquist and TuUberg] the fauna 

 here und^r consideration is found in the " Tetragraptus shales " overlying 

 the Ceratopyge limestone and succeeded by the Orthoceras limestone. The 

 latter also contains in Oeland [Holm] some of the species of this zone 

 (Tetragraptus bigsbyi and Phyll, angustifolius). In France, 

 a number of the characteristic species of Tetragraptus and Didymograptus 

 have been found in the graptolite schists of Boutoury near Cabrieres in 

 the Languedoc [Barrois] ; and Dichograptus octobrachiatus is 

 reported from Belgium [Malaise]. In Australia, well known Levis forms 

 have been recorded by McCoy and Etheridge jr from various localities of 

 Victoria. 



