22 C. U. Shepard—New Classification of Meteorites. 
of deposition are very much inclined and distorted. Near Black- 
bird till numerous dicotyledonous sein have been found, and 
many of these plants occur in a tzite so close-grainel that 
the lines of stratification are near| oe or cai obliterated, yet the 
impressions are distinct. This quartzit: forms a valuable quarry 
near Sioux City. The coal seam included in this formation, 
(Lower Cretaceous, No. 1) crops out forty miles up the Big Sioux, 
or within sixty miles of Sioux Falls. “Between Sioux City a nd 
- Yankton we have at least oni members of the Cretaceous se- 
ries. Near Fort James we find that two —— of — aa 
ceous series (Nos. 2 and 3) rest upon the quartz The surfac 
features of the whole country, with the soil pie ‘drift, paticate 
that the immediate underlying rocks are of Cretaceons age. 
it not possible therefore, that the quartzites that include the pipe- 
stone bed, belong to the supra- are eh pakic ae Sahat 
or even to an extension downward of Cret: 
Prof. Hall, in an interesting geological memoir, rae recently 
before the American Philosophical Society, gives an penne: - 
a tour into Western Minnesota, and many of the rock exposu 
which he describes must be of the same age with those inti 
in this paper. He seems to 5 proceeded west from St. Paul to 
St. Peters and Fort Ridgely on the Minnesota river. From Fort 
Ridgely he continued west to Lake Shetek, which is not more 
than forty miles from the pipestone bed. Prof. Hall describes 
a wall of red quartzite at this locality, which he thinks is o 
same age and character with that at Pipestone creek. Iam con- 
vinced that not only the rock at Lake Shetek, but at many other 
localities which he describes with great care, are of the same 
age. I was informed by intelligent land surveyors in Dakota 
and Minnesota, that these red quartzite exposures extend very 
far to the north. Prof. Hall regards these quartzites as of the age 
of the Huronian series. is Opportunities for tracing these 
rocks from the north and east were excellent, and his opinion is 
entitled to great weight. 
Acad, Nat. Sci. Philadelphia, Nov. 10, 1866. 
Art. IV.—New Classification of Meteorites, with an Enumeration 
of Meteorite Specees ; by CHARLES UPHAM SHEPARD. 
THE arrangement here proposed differs so widely from the two 
formerly put forth by me, as to be really new. The changes 
introduced will, I trust, appear as flowing naturally from the 
recent progress ‘of the study. The localities by which the system 
is illustrated are such as are represented in my collection, now 
deposited in Amherst College. A number of localities found on 
my previous lists as well as upon those of others, are omit 
