Key to genera of Vespertilionidae in Korea
1 Nostrils tubular and protruded outwards............................................................... Murina
- Nostrils not tubular and do not protruded outwards........................................................... 2
2 Premolar 2/3; ear length> 30 mm; ears joined across forehead............................................ Plecotus
- Premolar 1/2, 2/2, or 3/3; ear length <20 mm; ears separated................................................... 3
3 Premolar 3/3; 38 teeth; slender, straight, pointed, upright tragus; tragus length 3 times greatest width).............. Myotis
- Premolar 1/2 or 2/2; tragus not pointed (rounded or mushroom shape)............................................ 4
4 Dense fur on plagiopatagium between humerus and femur; length 5 th finger a little longer than 4 th metacarpal, reaching near midpoint of first phalanx)......................................................................... Nyctalus
- Dense fur absent on plagiopatagium between humerus and femur................................................ 5
5 Ears wide (> 10 mm); premolar 1/2; 32 teeth................................................................ 6
- Ears narrow (<8 mm); premolar usually 2/2; 34 teeth (small or absent upper anterior premolar in Hypsugo).............. 7
6 Conspicuously frosted dorsal pelage, long pale hair tips; ear almost reaching mouth; palatal emargination wider than long............................................................................................... Ƒespertilio
- Pelage not frosted; posterior margin of ear with a narrow furrow extending towards the corner of mouth ending before reaching mouth; palatal emargination longer than wide........................................................ Eptesicus
7 Tail beyond uropatagium <2 mm; post calcaneal lobe broad with well-developed keel....................... Pipistrellus
- Last 1 or 2 tail vertebrae 2–5 mm beyond uropatagium; post calcaneal lobe narrow and always without keel........ Hypsugo