with Descriptions of New Fossils. 215 
ered in it are chiefly Orthoceras and Straparollus, but the few 
Specimens we have found are so badly preserved that they are 
eae useless for the purpose of identifying the age of the for- 
mation, 
Catcirerous Sanp Grovp. 
This formation = fea ropassonk beneath the Burnet marble 
and consists of calea magnesian limestone, nearly pure lime- 
stone and chert. The. sual ey of the group may be 
understood from the following section 
s Section of Falls of Deer Creek, near 2 Baldene River, Burnet 
0.— 
No. 1. adentonlored ee tng ta with Pasir aa 
chert, 40 ft. 
see beds are more sper soir — 
of finer texture than the lower, - 299 ft. 
“ 3. Very hard, light gray pines with a nee tinge, 57 ft. 
At Marble ane Colorado river, just below the mouth of Flat-Rock 
creek, we have an interest ing section, showing the “deen of the 
Calciferous iad group with the overlying formations t 
Dark, Carboniferous Limestone with Pisin semire- 
ticulatus (2) arctic paplein: and numerous remains of 
Cr rinoidea, 
8S Aernations of sepa aoted brittle limesione ae dolomite 
(Burnet Marble), 90 ft. 
“8. Thick beds of very hard, brittle Sadat (Burnet Marble), 55 ft. 
“4. Calciferous sand group, consisting of light and dark 
gray, compact a fine- 5 sie —* in ee from one to sk 
six feet thi ick, 
45 ft. 
fluence 
At Mormon Mi is, on Hamilton pee is ‘nites above its con 
with the ‘Dokivede (Burnet county) we find the ge section, show- 
me bok @ Junction of the formation under notice with th otsdam sand- 
sto 
limre- 
No, 1 Massive beds of sub-crystalline, calcareo-magnesian [i 
h 
an variegated with brown and purple and forming roug a. 
“ 2. Gray micaceous soindstoi ‘made up a fine ron sie . 
ed with argillo-calcareous matter, : Wg eee 
Oey characterized the Calciferous san is 
ly seb gie in chs counties of San sf, an, MeO , 
Ieee fe Menard , Mason and toa limited extent in age og ie 
presence may in general be recognized by the rough and pictur- 
“sque appearance of the country where it prevails. 
