374 The American Geologist. December, i904. 
is interrupted by later cross dislocations within the Sakischima 
group, which is the southernmost in the belt and meets the east- 
ern coast of Formosa in the high and steep peninsula of Dom- 
kaku. From v. Richthofen's map, it would appear that the arc 
where it enters Formosa marks a dividing line between domin- 
ant strike directions to the northward and southward, and finds 
here its southward end. 
To the northward the arcs are joined to Kiusiu, the south- 
ernmost of the Japanese islands, and continued upon it, the out- 
er arc by a great fault along the eastern coast of the island, and 
the volcanic zone in the great Graben depression bounded by 
high and steep walls and terminated northward by an amphi- 
theater (Kesseleinsenkung). In the bottom of this depression 
are located important volcanic vents. This important depres- 
sion separates the two southern wings of the Palaeozoic base- 
ment. 
Formosa: Following the Chino-Japanese war, by which the 
Japanese came into possession of Formosa, an exploring ex- 
pedition was sent out in 1896, and what had before been known 
to science chiefly through its aspects from the sea gradually 
came to be fairly well known. It had been observed that the 
eastern coast was very steep and was backed by high moun- 
tains, two of which received from- navigators the names Sylvia 
and Morrison. The western aspect of the island, on the con- 
trary, was one of flatness. The sharply serrated eastern high 
range slopes away to the flat western coast. One of the most 
important discoveries' was the remarkable "Taito furrow," 
which sharply cuts ofif upon the east the connected massif of 
ancient rocks along an almost straight line 155 k. m. in length 
and directed N 20° E. This furrow is occupied by three distinct 
streams separated by low divides, two streams passing out at 
the ends of the furrow, while a third intermediate and T- 
shaped one escapes through a gorge in the eastern range. This 
eastern range is known as the Taito range. Between the Taito 
furrow and the similarly directed line about 50 k. m. to the 
westward, runs tlie dominating Taiwan range, with its peaks 
Sylvia, Kantaban and Morrison, respectively about 11.000, 
9,000 and 13,000 feet in height. These peaks also are in a line 
running N 20° E. Farther west follows a range consisting of 
Tertiarv rocks likewise directed N 20° E. \'. Richthofen adds : 
