There were a lot of accidents with those new fangled reels (see X:1) with that extra eighth note at the end of every measure and a lot of limbs were broken slipping around it or hopping over it, and they were called hop jigs or slip jigs because of that. Then a wise Scot figured out you could just wiggle around it, like in the 2nd dance below.

X:1
T:THE REEL OF HARDEN
N:Oswald's Caledonian Pocket Companion
L:1/8
M:9/8
K:Am
B2G GGG Bdg|B2G GGG cAF|~B2G GGG gde|f2F (ABcA)f2A::\
g2dg2dgdB|g2dgdef2A|g2d~e2d Bde|f2F (A/B/c)Bf2A:|]

x:2
T:THE SCOTS WRIGGLE
N:Oswald's Caledonian Pocket Companion
L:1/8
M:9/8
K:D mixolydian
G2c~B2G (B/c/d)B|G2c~B2G efg|G2d~B2G dBG|F2A AFD (F/G/A)F|\
G2gg2G B/c/dB|G2gg2e (f/g/a)f|gfe dcB cde|~F2A AFD (F/G/A)F::\
G3 BGB (A/B/cA)|G3 BGB (A/B/c)A|G3 BGB (A/B/c)A|\
(B/c/d)B gdB AFD:|]