“Sra pt a ve 
230 Geological Reports of the State of New York. 
organic remains. The Rochester and gypseous shales are given 
as the equivalent of the Wenlock Shale of Murchison. The fos- 
sils placed against Nos. 7, 8 and 9, belong to the lower rocks, as 
Triarthrus and Isotelus to the Trenton limestones. Against No. 
9 should staud the shell Pentamerus oblongus, or if a trilobite — . 
must be introduced, it can be neither of those mentioned, but 
Asaphus longicaudatus. Where is the statement that the remains 
against Nos. 5—9 have been found even as high as the Rochester 
shale ? 
The limestone of Tully, or Tully limestone, is considered as 
identified with the Aymestry limestone of Murchison by two spe- 
cies of shells, Avicula reticulata and Alrypa didyma. p. 31. 
The fronds of Fucoides are often very prominent, but the 
structure like that of the rock in which they exist; of other 
plants, scarely more than impressions remain. The petrifying 
material of the corals is commonly siliceous earth; but of the 
Crinoidea, is limestone, whether they lie in calcareous or siliceous 
rock. p. 40. 
Several new genera and many new species are described, and 
many yet remain for the final report. pp. 48 
Several important corrections are announced. 
The Calymene Blumenbachii, as the trilobite in the Trenton 
limestone was called, Mr. Conrad considers a new and unde- 
scribed species; it is named by him Calymene senaria, from its 
place in so old a rock. It no longer is an instance of an animal 
that “escaped into remote seas,” and lived in a much later era 
than its period of destruction here. “ Calymene platys of Green” 
is stated to be C. Blumenbachii, and to agree with it in place 
also; so that this fossil is found where it ought to be, and no 
longer throws uncertainty over the age of our rocks. 
The evidence is now thought conclusive by Mr. Conrad against 
the existence of any fresh-water shells in the strata below the car- 
boniferous, “in which Uniones occur in Pennsylvania.” ‘The 
supposed Unio in the sandstone at Medina turns out to be some- 
thing else, the Planorbis “ probably a Bellerophon,” and another 
to bie: Sh allied genus. This correction is the more neces- 
shells “are associated with two marine genera, Liu- 
gula and Orthocera.” Probably the existence of fresh-water 
fossils in that sandstone had been a matter of high surprise to 
most geologists ; the evidence decides the case. p. 41. : 
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