[MATTHEW] NOTES ON CAMBRIAN FAUNAS, No. 12 47 
To avoid confusion in the use of terms the writer has inserted in 
the sixth column of the accompanying table the larger divisions of 
the Cambrian System as they have been used in England, and shown 
how they compare with the Acadian names (in the fourth and fifth 
columns) and with the divisions and arrangement lately used in America. 
The first three columns are intended to show in a general way the 
approximate thickness of the Cambrian measures in the St. John 
district, the composition of these measures and the genera of trilobites, 
&c., which characterize the several parts of the Cambrian system as 
here displayed. 
It is surprising to see how few and how far apart are the districts- 
in eastern North America where the Cambrian rocks have been recoge 
nized by determinable fossils, and where such Cambrian age can be 
determined without any reasonable doubt. These districts ars 
six: four on the Atlantic coast and two in the interior. By their fauna- 
these districts naturally fall into two groups separated by the distinct- 
ness of their species and evidently belonging to two separate zoological 
provinces. By the genera they have yielded those of the two interior 
districts are clearly allied to the Cambrian types of western North 
America, and whether we attribute resemblance to a uniformity of 
temperature of the Cambrian seas in that region, or to other causes, 
the faunal grouping of the two interior districts is with those of the 
Rocky Mountains, or even distant China, they clearly had a different 
biological history from the other eastern exposures. As regards the 
faunas contained in the Cambrian rocks along the Atlantic coast, 
especially in the Paradoxides Zone, many close links of relationship are 
noticeable in the fossils with those of Europe; and this may be traced 
from the Baltic Sea to Massachuset’s Bay on the coast of New England, 
as though a similarity of temperature or connection shallows of the 
ocean had prevailed for the whole width of the Atlantic ocean at some 
part of its extent. 
The Cambrian basins of the St. John district. 
The. area which we have alluded to above as one of the four dis- 
tricts of the Atlantic coast, is that which forms the strata &c., described 
in the preceding table, and is the basis of the following remarks. 
The district shows three basins of which the southermost exhibits 
the full series of Cambrian rocks, which in the other basins are cur- 
tailed by transgression or erosion. The transgression, which is ac- 
companied by evidences of a slight discordance (conglomerates, &c.) 
is indicated on the table by a double cross-line, for at this point in the 
