1
Figure 314 is an accidental whorl, combining a loop and a tented arch.
2
Figure 316 at first glance appears to be an accidental whorl, but on closer inspection it proves to be a loop.
3
Forty minutes later I descended, knowing a dizzying amount about tented arches, ulnar loops, and accidental whorls.
4
The patterns referred to are usually double loops, though accidental whorls and loops sometimes present the same problems.