Review of Recent Geologfcal Liternture. 273 
with them are sink holes containing? water only after heavy rains. These 
basins form chains and finally pass into the form of the arroyo. Havvorth 
believes that the soft sands settle and form the sink holes, and the water 
collects and drains down to the underlying clay. When the under sur- 
face is saturated the surface slips and creeps downward until the sep- 
arate basins draw together and form the arroyo. This interesting 
theory seems to accord well with the observed facts. 
The individual streams are described and discussed, and the Arkan- 
sas river might perhaps be taken as a type of these streams. This river 
was at one time 50 feet or more lower than at the present time, deposi- 
tion is now in progress, gradually building the flood plain higher. A 
prominent feature of this river is the great bend commencing in the 
eastern part of Ford county. In an earlier epoch the river doubtless 
passed directly eastward, emerging from the state near its present loca- 
tion. As the river cut down into the S(jft Dakota it followed this for- 
mation northward until base level was reached, and the river could no 
longer corrode the Dakota bluffs. It was prevented from turning 
northward farther west, for the north bank was formed of the resistant 
Benton limestone until eastern Ford county was reached. 
Professor Prosser's name is closely connected with the progress of 
knowledge of Kansas geology through his excellent work on the Permi- 
an, and his paper in this volume on the Upper Permian and the Lower 
Cretaceous will be read with interest. A review of former work 
is given, showing that considerable difference of opinion has existed 
concerning the line of division between the Permian and Cretaceous in 
Kansas. The upper fossiliferous shales and limestones forming the Ma- 
rion formation are overlain by the Wellington non-fossiliferous beds, 
which have a maximum thickness of 445 feet. Above this group is the 
Cimarron series, or Red Vjeds, consisting of red sandstone and shales 
without fossils and a layer of gypsum fifty feet in thickness. As there 
is no break between this series and the preceding, these rocks are pro- 
visionally referred to the Permian. The Red beds are clearly separated 
from the Comanche by an eroded surface. The second part of profes- 
sor Prosser's paper is devoted to the Lower Cretaceous. He refers all 
the Cretaceous deposits, as far as investigated south of the .Arkansas 
river, to the Comanche, which has two divisions separated by lithologi- 
cal and paleontological characters. First, the Cheyenne sandstone, 
which is a coarse grained, friable sandstone, about 50 feet thick, with 
rugged outcrop and containing fossil plants. Second, the Kiowa shales 
with their greatest thickness, in Clark county, 140 feet. The rocks are 
black and gray shales with vertebrate and invertebrate fossils. The 
distribution of the rocks is given with sections showing the order and 
thickness of the subdivisions. North of the Arkansas river, Kiowa 
shales are found at a number of isolated localities, reaching farthest 
north in Saline county. 
The third paper is a description of the Upper Cretaceous of Kansas 
by W. N. L:)gau with an introduction by professor Havvorth. These de- 
posits cover an area in northern central Kansas, of i!5,000 square miles, 
