Classification of Cambrian Rocks. 309 
Of the sections of Cambrian Rocks in Acadia exhibited 
on the Table I, page 308, three are from theSt. John Basin, 
and the fourth from the northern basin in Kings Co., and 
they show clearly the varying thickness of the deposits of 
Division or Stage 1. in the different districts; this feature 
is much more noticeable in the lower bands (a and b) than 
in the upper ¢ and @). 
The most continuous and complete section found, is that 
on Hanford Brook, where the Cambrian measures are now 
separated from the rest of the St. John Basin by a low 
ridge of pre-Cambrian rocks ; and from the differences that 
are observable in the details of the sections on the two 
sides of this ridge, it is probable that it existed in Cam- 
brian times (compare the 3rd and 5th sections). Band 6 has 
its greatest thickness in the more distant basin in King’s 
Co., (see fourth section), but does not show so much variety 
in the sedimentation as at the easterly exposures in the 
St. John Basin. 
In this district at Hanford Brook, the fauna of 1 6 pre- 
sents itself in considerable variety. At the base, forty feet 
of the dark gray sandstone contains Ellipsocephalus and 
fragments of other trilobites; four entomostracans, viz., 
Hipponicharion and three species of Leperditia, which 
latter are remarkable for their thick tests, and pitted sur- 
faces, and six species of brachiopods of the genera Acrothele, 
Acrotreta, Linnarssonia and Lingulella. 
These sandstones are followed by fifty feet of compara- 
tively barren, dark grey, sandy shales; and they by thirty 
feet of hard, purple-streaked sandstones, in which occurs an 
Agraulos of the form of A. (Arionellus) primevus of the bed 
b in Sweden, and the peculiar Hyalithoid shell Diplotheca, 
as well as numerous tracks of Psammichnites. 
The olive grey shale, thirty feet thick, above this sand- 
stone, is comparatively barren, but has yielded the two 
species of Beyrichona, a genus which has points of resem- 
blance to Aristoze of Barrande. 
The upper bed of b, twenty feet thick, is that already 
described as being cut up by worm burrows. In it the 
