e shoulders at a right angle. It cannot be classified as an
accidental as the patterns are all of the same type, i.e., tented
arches. An accidental type of whorl is a combination of two or more
_different_ types of patterns exclusive of the plain arch.

Figure 312 is a loop. It cannot be classified as a whorl of the double
loop type because the formation above the lower loop is too pointed
and it also has an appendage abutting upon it at a right angle.

Figure 313 at first glance appears to be a whorl of the double loop
type. Upon closer inspection, however, it will be noticed that there
are no delta formations other than on the recurves. There are, then,
two tented arch formations. As two patterns of the same type cannot
form an accidental whorl, the impression must be classified as a
tented arch.

[Illustration: 313]

[Illustration: 314]

Figure 314 is an accidental whorl, combining a loop and a tented arch.
The tented arch is directly beneath the innermost loop, and is of the
upthrust type.

Figure 315 consists of a loop over a dot with an apparent second
delta. This pattern must be classified as a loop, as a dot may not be
considered an upthrust unless elongated vertically.

[Illustration: 315]

[Illustration: 316]

[Illustration: 317]

Even though a dot may be as thick and heavy as the surrounding ridges,
it may be considered only in ridge counting or fixing a delta.

Figure 316 at first glance appears to be an accidental whorl, but on
closer inspection it proves to be a loop. Although there are three
delta formations present, it should be observed that recurving ridges
appear in front of only one (D-1).

Figure 317 has the general appearance of a loop. The looping ridge A,
at the center, has an appendage B abutting upon its recurve. The
abutment is at right angles and therefore spoils the recurve. The
pattern is a tented arch.

Figure 318 is a tented arch which approaches both the loop and the
whorl type patterns. It cannot be considered a whorl, however, as the
recurve on the left is spoiled by an appendage (figs. 58 and 59). Nor
can it be a loop because there is no ridge count across a looping
ridge. The pattern, then, is a tented arch of the type possessing two
of the basic characteristics of the loop and lacking the third. The
delta and the sufficient recurve are present but the ridge count is
missing.

Figure 319 seems at first glance to be a double loop. It will be
noted, however, that th