'The Taconic — Marcou. 69 
the evidences given by Mr. Dana in Atner. Journ. Sci'.y 1872 
to 1887. Only in his Resume Mr. Walcott says that his No. 3 
"is essentially a repetition of the Low^er Silurian (Ordovician) 
section of the Champlain valley. It differs in lithologic details 
and in having a less abundant fauna in the Taconic area," {^Loc. 
cit. p. 320); an admission of differences vv^hich at first seem of 
no consequence, but w^hich involve the entire question of age 
and synchronism. 
Mr. Dana's pal.eontological evidences. — As No. 3 is 
the strongest point in the controversy on the part of the adver- 
saries of the Taconic, I shall show what are the palaeontological 
proofs given and their value. 
The two papers by Mr. Dana, entitled: "A. Wing's discov- 
eries in Vermont," (^Amer. Jourji. Sci., vol. xiii, p. 332 and p. 
405, 1S77,) and "Geological age of the Taconic system," 
i^^tiart. jfozcrtt. Geol. Soc, London, vol. xxxviii, p. 397, 1882,) 
contain all the palaeontology of the question. No plates; no 
description of species; only the names and a few words of ex- 
planation, which is much to be regretted, for observers who 
want to give such a decided view on difficult points, ought to 
have taken proper care to produce proofs, upon which everyone 
can form an opinion. 
. In his paper of 1877, Mr. Dana says, p. 388, that at a marble 
quarry of West Rutland, two fossils were found, one like Pleu- 
rotomaria staminea, and a plate of Pleurocystites te?iuiradiatus, 
determined by Billings in June, 1871. Mr. Dana did not quote 
the part of Billings' letter, in which he twice repeats the word 
obscure saying: '•Encrinites and obscure fossils, stipposed io be 
Trenton;" and "numerous o^^j-cwre/j' preserved forms like T'/e?^- 
rotomaria staminea.'''' Nay, more, the quotation given by Mr. 
Dana is: "I think this collection is Chazy. The cystidean 
Pleurocystites tenuiradiatus, is a never failing guide to the 
Chazy; at least it is so on the west side of lake Champlain;" 
when all Billings said was: "I think this collection is Chazy;" 
the rest of the paragraph has been added by Mr. Dana, and is 
not from Billings. At other parts of the vicinity of Rutland, 
encrinal disks, a shell resembling an Euomphalus and a Mur- 
chisonia were found. 
The only conclusion to be drawn is that we have at Rutland, 
