on the side from which it entered but has a tendency to do so. In this
case, all the requirements of the loop have been met, and consequently
it is classified as such.

[Illustration: 58]

[Illustration: 59]

[Illustration: 60]

Figure 62 shows a ridge entering on one side of the impression,
recurving, and passing beyond an imaginary line drawn from the delta
to the core, although opposite from the pattern shown in figure 61.
After passing the imaginary line, the recurving ridge does not
terminate on the side of the impression from which it entered, but it
has a tendency to do so, and the pattern is, therefore, a loop.

In figure 63, a ridge enters on one side of the impression and then
recurves, containing two rods within it, each of which rises as high
as the shoulder of the loop. From our study of cores, we know that the
top of the rod more distant from the delta is the core, but the
recurving ridge does not pass the imaginary line. For that reason the
pattern is not classified as a loop, but is given the preferential
classification of a tented arch due to the lack of one of the loop
requisites. The proper location of the core and delta is of extreme
importance, for an error in the location of either might cause this
pattern to be classified as a loop.

Figure 64 reflects a similar condition.

[Illustration: 61]

[Illustration: 62]

[Illustration: 63]

[Illustration: 64]

[Illustration: 65]

[Illustration: 66]

In figure 65, there is a looping ridge A which enters on one side of
the impression. The ridges B and C are the type lines. As determined
by rules already stated, the location of the core and the location of
the delta are shown, and if an imaginary line were placed on the core
and delta, the recurving ridge A would cross it. This is another
figure showing a ridge which does not terminate on the side of the
impression from which it entered but tends to do so, and, therefore,
is considered as a loop.

In figure 66, we have a print which is similar in many respects to the
one described in the preceding paragraph, but here the recurving ridge
A continues and tends to terminate on the _opposite_ side of the
impression from which it entered. For this reason the pattern is not a
loop, but a tented arch. The recurving ridge must touch or pass the
imaginary line between delta and core and at least tend to pass out
toward the side from which it entered, so that a ridge count of at
least one can be