Lower and Middle Taconic — Marcou. 371 
Schmidtia mickwitzi and the Scandinavian Hohnia kjerulU 
as true Olenelli of the original typical form of Georgia, it is 
to be supposed that his Olenellus hroeggeri is no more an 
Olenellus than the trilobite of Mickwitz and the trilobite of 
Kjerulf. 
The whole synchronism of the Esthonian and Scandinavian 
formations with the Georgia formation is based entirely, accord- 
ing to Mr. Walcott's views, on the genus Olenellus. But it 
is certain that trilobites have been placed in that genus, which 
truly belong to other genera, and we are lead to conclude that 
a too hasty generalization has been given by Messrs. Walcott 
and Lapworth in their three papers entitled : "Stratigraphical 
Succession of the Cambrian Faunas in North America" 
(Nature, Oct. 4, 1888) ; "On the Discovery of the Olenellus 
Fauna in the Lower Cambrian Rocks of Britain" ( Geol. 
Magaz., Nov., 1888 reprinted in Nature^ Dec. 27, 1888) ; and 
"Strati graphic Position of the Olenellus Fauna in North Amer- 
ica and Europe" (^Amer. Jr. Sc, May and June, 1889) ; where 
we read the following paragraphs : 1. "The brief paper (of Mr, 
Walcott). . . puts an end to a controversy between European 
and American Geologifsts, and brings into harmony the se- 
quence and palaeontology of the Cambrian Faunas on both 
sides of the Atlantic." 2. "It affords me (Mr. Walcott) pleas- 
ure to recognize the work of the Swedish geologists, and to 
fully coincide with their results, and thus finally establish on 
the two continents the true order of succession of the oldest 
known Paleozoic fauna." 3. "The relative position of the Mid- 
dle and Lower Cambrian faunas is now changed in the Amer- 
ican scheme of classification, the Paradoxides zone being re- 
moved to the Middle, and the Olenellus zone to the Lower 
division." 4. In all my (Mr. Walcott) previous papers the 
term Middle Cambrian is to be changed to Lower Cambrian, 
and Lower Cambrian to Middle Cambrian." We have there a 
chasfiS-croise of Mr. Walcott, and a too hasty generalization of 
Mr. Lapworth, based on erroneous interpretation of fossil gen- 
era, and not onl}'- a total want of stratigraphic proofs but 
against the stratigraphy of the typical localities of Georgia and 
Bald mountain. 
The truth is, that Mr. Walcott made a first mistake, in re- 
jecting Murray and Howley's observations on the stratigraphy 
of Newfoundland in his "Second contribution to the Cambrian 
