12 Tke Taconic — Marcou. 
trilincatiis after a disagreement between Messrs. Ford and 
Walcott, and finally they have accepted the genus as certainly 
primordial, wavering between four names and rejecting all the 
time Atops. It is for all impartial observers to say, whether it 
would not have been better for the progress of palaeontology, to 
have adopted at once the determination of Dr. Emmons. 
EU'iptoccphalits asafhoides^ another Taconic fossil described 
by Emmons in 1S44, is also a good species and a good genus, 
entirely primordial. Barrande in 1S61, accepts the species, using 
the name Paradoxides for the genus, following Emmons, who 
in his Ma7tual of Geology^ i860, p. 280, refers it to that genus. 
Mr. J. Hall calls it first an Olenus^ then Barra?idia, then Olen- 
ellus\ besides he objects to EUlftocephalus on account of Ellip- 
socephalus oiZankex; and regards it as an Ogygia or OlenuSf 
saying that "it evidently belongs to a Lower Silurian type;" he 
does not mean a jDrimordial or a type special to the Taconic; no, 
on the contrary, he wants to take it out from the primordial, as 
that fauna was then [ 1S47] known in Scandinavia and Bohemia. 
Mr, Hall regarded then and thirteen years after the " Olenus 
zone" of Hisinger and the primordial of Barrande, as placed, 
by those two savants^ in a wrong stratigraphical position; and 
he tried to correct the European stratigraphy, which according 
to his view ought to have placed the primordial above the 
second fauna, instead of being below it. 
If the name ElUptocephahis asaphoides of Emmons, and its 
geological position of pre-Potsdam had been accepted by the 
paleontologist of New York, we should have been spared the 
confusion created by three others generic names, and the plac- 
ing of the Olouis zone above the Lorraine shales, that is to say, 
above the second fauna, a fact which astonished so much Ange- 
la! and Barrande. 
Microdisais — In 1855, ^^' Emmons, pursuing his studies of 
the Taconic notwithstanding the opposition made by its com- 
bined adversaries, described another new form of primordial tril- 
obite, Allcrodisais g?iadricostat?/s. Barrande in 1861, regards 
the specimen figured by Emmons and his very short descrip- 
tion as too incomplete, and not well preserved enough "to judge 
with certainty the character of this trilobite." Since then Mr. 
J. W. Salter in 1864, from numerous specimens found in the 
