Lower and Middle Taconic. — Marcou. 361 
found good fragments of a trilobite of the Paradoxidean type. 
He placed fossils and sections with all his notes in the hands 
of professor F. Schmidt, a fellow of the Imperial Academy of 
St. Petersburg, who read a most interesting paper before that 
academy, the 16th February, 1888, under the title : "Ueber 
eine neuentdeckte untercambrische fauna in Estland." Mem. 
Acad. Imp. Sciences, 8t. Peter shouT(j., vii serie, tome xxxvi, No. 
2). Later on, in November 1888, professor F. Schmidt read 
another paper : "Weitere Beitriige zur Kenntniss des Olenellus 
mickwitzP^ (Biilletifi Acad. I?np. Scietices, St. Petersbourg, 
tome XXXIII, p. 191). 
The resume of the discoveries of both Mickwitz and Schmidt 
is : that below the "Fucoid sandstone" of Sweden, recognized 
without any possible doubt near Reval, there exists at Striet- 
berg a series of blue clay with subordinate layers of sandstone 
six hundred feet thick, resting on the Finland granite. In the 
upper beds of the blue clay the following fossils have been 
found : Olenellus 7nickwitsi, Scenella discinoides, Seen.? 
ttiberculata, Michwitzia monilifera., Oholella? Discinaf 
YolbortJiella tenuis, Platysolenites a)iiiquissimus, Iledusites 
lindstroemi, Primitiaf and Fraena tenella. All the forms of 
these fossils are very old ; and a study of the two plates which 
accompany the important memoir of i^rofessor Schmidt im- 
presses the idea that we have there the oldest fauna yet 
found. It is not that no other fossil exists, and that we do 
not possess already a few traces of fossil remains found below 
the Esthonian as we have seen previously in the Newfound- 
landian ; but it is a fact that until now no collection of a cer- 
tain number of fossils, sufficientlj' numerous to be called a 
fauna, has been found, as old as the Esthonian fauna of Russia. 
Several of the forms of these fossils, more especially the only 
trilobite found, which is the oldest trilobite so far known in 
the world, indicate that something older must exist, and that 
one day more fossil animals will Ije found at a lower stage 
than the Esthonian formation, in theNewfoundlandian strata. 
In regard to the trilobites, justly regarded as the most im- 
portant and useful family of fossils for the Palaeozoic- series, 
as the Cephalopoda are for the Mesozoic series, the two most 
primitive forms, with the simplest organization, are Agnostus 
and MicrodisGus which have not yet been found in the Infra- 
Primordial fauna or Lower Taconic. 
