THE KANSAS RIVER 
181 
The western termini of the east-west Antillean axes of the 
Caribbean half of Central America, which are buried in western 
Guatemala, Honduras, and Costa Rica by the overlying volcanic 
masses, are not so limited on the Pacific side, but continue across 
Panama. On entering this state from Costa Rica signs of recent 
volcanic activity cease, and the continuity of the chain of high 
Central American summits is succeeded by the still more broken 
and apparently inexplicable lower-lying Isthmian topography. 
The isthmus of Panama can now be accurately defined as the 
stretch of land l 3 ung east of the southern end of the Central 
American region of active volcanoes (commonly called the Costa 
Rican volcanic plateau) and extending to the northern termi- 
nation of the Andes. Its limit on the east is Rio Atrato, which 
flows northward from the equator along the valley marking the 
eastern flank of the Andes ; on the west it is limited b}' the 
southern boundary of the republic of Costa Rica, extending 
from Burica Point to the island of Veraguas and thence between 
the meridians of 79° 15' and 82° for a distance of 180 miles. 
The axial trend of the Isthmian region is east and west, or in a 
direction contrary to the north and south continental trends, 
and is conformable with the Antillean axes. 
The Great Antilles lie along the line of east-west corrugations 
and a]:>parently represent nodes of greater elevation whereby the 
surfaces of these islands were projected above the waters as 
islands, which have persisted without continental connection or 
union with each other since their origin. 
[XoTE.— The foregoing article is published by permission of Professor Agassiz, under 
whose auspices the writer conducted his investigations in the region described.] 
THE KANSAS RIVER 
By Arthur P. Davis 
United Slnles Geoloijiad Survey 
The Kansas river jtroper is formed bv the junction of the 
Smok}' Hill and Rcpultlican forks, at Fort Rile}', in Davis county, 
Kansas, about 140 miles from where it enijttics into the Mis- 
souri. It is OIK! of the liest exani])les of ;i western stream whose 
drainage lies entirely in a jdains region, with no mountain tribu- 
taries. Its basin extends from eastern C’olorado to the Missouri 
