WII Kiim 8 K A -" D ] OATAWISSA SECTION. 67 
affect the distribution of the species of a fauna. The succession of 
advantageous and adverse conditions of life at a given locality leads to 
the frequent shifting of position of some of the individuals of a fauna, 
and sometimes to the migration of the entire fauna. The overlap of 
faunas, the change in the composition of faunas at different horizons, 
and the modification of species in ascending can be studied in a satis- 
factory manner only in connection with the rock sections in which 
these changes are recorded. It is believed that the present method of 
presenting paleontological and stratigraphical data in faunal cross 
sections will throw much light on such problems and be most effective 
in working out the life histoiy of faunas. 
The accompanying sections are intended primarily as a contribution 
to our knowledge of the geographical distribution and geological 
range of Devonian fossil faunas, and as an aid in the correlation of the 
upper Devonian formations of Pennsylvania and New York. 
THE CATAWISSA SECTION, COLUMBIA COUNTY, PA. 
DESCRIPTION OF SECTION. 
By E. M. Kindle. 
Susquehanna River cuts across the strike of the southward-dipping 
beds of the Montour anticline between the town of Catawissa and East 
Bloomsburg station, exposing in a continuous section the beds of the 
Devonian from the Hamilton formation up to the lowest " red beds." 
The work of the river in exposing the strata, which dip southward at 
an angle of 35° to 45°, has been supplemented by the construction of 
the Pennsylvania Railroad along its east bank, and the resulting sec- 
tion is probably not surpassed, if equaled, by any other in Pennsyl- 
vania in the opportunity which it affords for the study of upper 
Devonian faunas. 
The lithological characteristics of the several beds are shown in the 
accompanying detailed section, which is followed b} 7 lists of the fossils 
obtained from each fossiliferous zone. 
Section 1453 A, at Catawissa, Pa. a 
Ft. in. 
72. (1) Red shales, dip S. 10 E. 30°-35° 50 
71. (2) Sandstone, greenish, massive, visible 10 
70. (3) Concealed 110 
69. (4) Greenish-gray sandstones, some shaly and also some reddish -brown 
sandstones 200 
68. (5) Sandstone, gray, massive 10 
67. (6) Red shale, sandy 100 
a Numbers in parentheses refer to corresponding divisions of White's section, Second Pennsylvania 
Geol. Survey, Rept. G 7, p. 285. 
