52 
ON THE GEOLOGY AND NATURAL HISTORY 
30. Hard, heavy-bedded, white argillaceous limestone, containing Monotis and Avicula. Ogden ferry, and 
below there , .... ............. 5 
31. Very thinly laminated dark green shale. Three miles nearly east of Ogden ferry, on McDowell's 
creek • also at Manhattan on the Kansas, ........... 1 
32. Light greenish and flesh-colored hard argillaceous limestone, with Spirifer cameratus. This is the 
highest horizon at which we found this species. Same localities, ....... 3 
33. Alternations of bluish, green, and red, more or less calcareous laminated clays, light gray limestones and 
claystones, with Pecten, Monotis, and fragments of Crinoid columns. Same localities, . . .30 
34. Alternations of bluish, purple, and ash-colored calcareous clays, passing at places into claystones, and con¬ 
taining in a thin bed near the middle, Spirifer planoconvexa, Spirigera sultilita, Product us splendens ?, 
Rhynchonella Uta, &c. Locality same as preceding, ......... 12 
35. Blue, light gray, and greenish clays, with occasional harder seams and layers of cla 3 T stone and limestone. 
Same locality, ................ 33 
36. Somewhat laminated claystone of light gray color, with more or less calc spar near lower part. Manhattan, 19 
37. Alternations of dark gray and blue soft decomposing argillaceous limestone, with dark laminated clays, or 
soft shale, containing great quantities of Fusulina cylindrica, F. cylindrica var. ventricosa, Piscina 
Munhattanensis, Ohcetetes, and fragments of Crinoids; also, Chonetes, Verneuiliana, C. mucronata, 
Productus splendens ?, Retzia Mormonii, Rhynchonella Uta, Spirigera sultilita, Spirifer cameratus, 
S planoconvexa, Enomplialus near E. rugosus, and Synocladia Lise rial is ; also Cladod us occidental is. 
Locality, same as last, . . . . . . . . . . . . . .18 
38. Soft bluish shale, with yellow laminated arenaceous seams below, containing Fucoidal markings. Same 
locality, ................. 25 
39. Two layers gray argillo-calcareous rock, separated by two feet of dark green and ash-colored clays. The 
calcareous beds contain fragments of Crinoids, Chonetes, and Myalina of undetermined species. Same 
locality as last, ................ 4 ? 
40. Light greenish, yellow, and gray clays and claystones, extending down nearly to high water mark of the 
Kansas, opposite the mouth of Blue river, ........... 27 
The foregoing general section of the strata seen along the valley of Kansas and Smoky 
Hill rivers, from the mouth of Blue river to the 98th degree of west longitude, is presented 
in its present form more with a view of illustrating the vertical range of the organic re¬ 
mains found in these rocks, than as an attempt to group the beds into formations that may 
he expected to preserve their distinctive lithological characters throughout areas of any 
great extent. As this has necessarily been done from a knowledge of only a portion of 
the fossils characterizing these strata, it is quite probable, when more extensive collections 
are obtained, that it may he found necessary, even on this principle, to classify and group 
the beds somewhat differently. We are also aware that some of these beds probably in¬ 
crease or diminish greatly in thickness, or may even entirely thin out, at no very great 
distances from the localities where we saw them. 
Among the more peculiar features of the series of rocks represented by this general 
section, and in part by the preceding local sections, may be mentioned, first, the great 
