14 The Tacontc — Marcou. 
Atops trUineatiis as identical with the Calynicuc ( Triarthrus^ 
heckii. 
Di". Emmons rec^arded the graptolites of Iloosic as different 
from any of those found in the Utica slate and Lorraine shale, 
and I fully concur with him and believe him; while on the con- 
trary I distrust all that has been said on the subject by Messrs. 
J. Hall and Walcott. Mr. C. Lapworth, the English authority 
on the subject, and who has studied that very low and enigmatic 
fossil called Graptol/'t/nna, as a specialty, not only finds 
varieties from that species of Diphg)'aptns prlstis^ which he 
identifies with the Diplotrraptiis foUaccus of England, but 
even goes so far as to say that it "ranges up through at least 
three complete zones' At Covefields, near Quebec, Mr. Lap- 
worth recognized three Aarieties of the true D. pristis, which 
he called, i, basi/ic7ts^ 3, cofife/'tus^ '^^ platydciis. He identified 
the sj^ecies, not the varieties, at several localities in the vicinity 
of Quebec. Besides he quotes four other grajDtolites as "spe- 
cies of long range." All this shows that the use of graptolites 
as characteristic fossils, is attended with a want of exactness, 
both in the determination of species and in their fixity in strata. 
But this is not all; the use made of them by Mr. Walcott re- 
quires another citation and calls for a remark. He says: "Mr. 
C. E. Beecher found three of the same species of graptolites 
( Cl'nn. bicor/iis^ III era. ramosiis and Diplogr. mucronatus^ as 
those foimd by me in the "Taconic slates" of Washington and 
Rensselaer counties associated with brachiopoda five species; la- 
mellibranchiata, sixteen species; pteropoda, two species; gastero- 
poda three species; cephalopoda, two species; annelida,one spe- 
cies ; Crustacea one species, and trilobites two species." [ /. c.^foot- 
ftote., p. 323.] Such a fine second fauna and even of the upper 
part of the second fauna, indicates absolutely that north of the 
Dudley observatory on the line of the New York Central rail- 
road, we have the .Utica slate. But it does not follow that the 
other locality at Kenwood near Albany where graptolites have 
long been known to exist, belongs to the same formation. For 
there no trace of the second fauna exists, except a single oboloid 
shell. A fauna so rich in larneUibraiicliiata and containing 
two trilobites, the Triarthriis beckii and Trin7icle7is co}ice?i- 
iric?is, cannot be confined to a single point of the Hudson 
