74 PALEOZOIC PALEONTOLOGY. 
Of this lst of forty-eight species, twenty-nine are described for the 
first time in the present report, and three of those previously described 
—Diphyphyllum integumentum Barr., Chonetes jerseyensis Weller 
and Proetus pachydermatus Barr.—came originally from the Decker 
Ferry fauna of New Jersey, and have not been reported elsewhere. 
This leaves but sixteen species in the fauna which may be used for 
direct comparison with other faunas. Of these sixteen species, six— 
Prismatophyllum inequalis (Hall), Stropheodonta bipartita (Hall), 
Orthothetes interstriatus( Hall), Atrupa? lamellata Hall, Whitfieldella 
nucleolata (Hall) and Calymene camerata Con.—were originally 
described from the Coralline limestone of Eastern New York, and 
are characteristic of the fauna of that formation. Among these six 
species are to be found some of the most characteristic species of 
the Decker Ferry fauna of New Jersey. Five of the sixteen species 
—Favosites pyriformis (Hall), Orthis flabellites Foerste, Reticularia 
bicostata (Van.), Pterinea emacerata (Con.) and Pteronites subplana 
(Hall)—have been described from the Niagaran faunas of the in- 
terior of the continent, but of these the two pelecypods are, perhaps, 
somewhat doubtful, and the identification of Orthis flabellites is not 
entirely satisfactory. Reticularia bicostata has only been recorded 
from the extreme eastern extension of the Niagaran strata,-in Oneida 
county, New York, and the beds of the Coralline limestone are known 
to extend as far west as Herkimer county, which is adjacent.to Oneida 
county on the east, and it is possible that careful field work would 
show the species to be really a member of the Coralline fauna and 
not of the typical Niagaran fauna; at any rate, the species is not 
one of the typical Niagaran species of the interior of the continent. 
The identification of Mavosites pyriformis is entirely satisfactory, and 
it seems to be the only really good representative of the Western 
Niagaran fauna. Three additional species—Halysites catenularia 
(Linn.), Leptena rhomboidalis (Wileck.) and Atrypa reticularis 
(Linn.)—occur, also, in the Niagaran faunas of the west, but they 
are all so cosmopolitan in their distribution that their presence gives 
little assistance towards a definite correlation of any fauna in which 
they occur. The association of the three species, however, is an excel- 
lent indication of the Silurian age of the fauna. ‘Two species— 
Pholidops ovata Hall and Rhynchospira formosa Hall—have heen 
identified with species normally occurring in the Helderbergian 
faunas. 
The evidence of these sixteen previously-described species, then, 
points most strongly to the Coralline age of the Decker Ferry fauna, 
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