in arch is the most simple of all fingerprint patterns, and it
is easily distinguished. Figures 107 to 118 are examples of the plain
arch. It will be noted that there may be various ridge formations such
as ending ridges, bifurcations, dots and islands involved in this type
of pattern, but they all tend to follow the general ridge contour;
i.e., they enter on one side, make a rise or wave in the center, and
flow or tend to flow out the other side.

[Illustration: 107]

[Illustration: 108]

[Illustration: 109]

[Illustration: 110]

Figures 119 and 120 are examples of plain arches which approximate
tented arches. Also, figure 121 is a plain arch approximating a tented
arch as the rising ridge cannot be considered an upthrust because it
is a continuous, and not an ending, ridge. (See following explanation
of the tented arch.)

[Illustration: 111]

[Illustration: 112]

[Illustration: 113]

[Illustration: 114]

[Illustration: 115]

[Illustration: 116]

[Illustration: 117]

[Illustration: 118]

[Illustration: 119]

[Illustration: 120]

[Illustration: 121]

_The tented arch_

In the tented arch, most of the ridges enter upon one side of the
impression and flow or tend to flow out upon the other side, as in the
plain arch type; however, the ridge or ridges at the center do not.
There are three types of tented arches:

- The type in which ridges at the center form a definite
angle; i.e., 90 deg. or less.

- The type in which one or more ridges at the center form an
upthrust. An upthrust is an ending ridge of any length
rising at a sufficient degree from the horizontal plane;
i.e., 45 deg. or more.

- The type approaching the loop type, possessing two of the
basic or essential characteristics of the loop, but lacking
the third.

Figures 122 to 133 are examples of the tented arch.

[Illustration: 122]

[Illustration: 123]

[Illustration: 124]

[Illustration: 125]

[Illustration: 126]

[Illustration: 127]

[Illustration: 128]

[Illustration: 129]

[Illustration: 130]

[Illustration: 131]

[Illustration: 132]

[Illustration: 133]

Figures 122 to 124 are of the type possessing an angle.

Figures 125 to 129 reflect the type possessing an upthrust.

Figures 130 to 133 show the type approaching the loop but lacking one
characteristic.

Tented arches and some forms of the loop are often confused. It should
be remembered by the reade