Key to species of Lamnostoma

1a. Eyes placed about 1/3 upper jaw from snout tip; gill opening lateral, anterior duplicate gill membrane absent; distance between dorsal fin origin and upper margin of gill opening 10.5–26.5% HL; no papilla on both of nostrils; 2 rows of white spots on lateral side of head meeting above gill opening and becoming a single row posteriorly, and forming a “Y”.............................................................................. Lamnostoma mindora (Jordan & Richardson, 1908)

1b. Eyes placed near the midpoint of upper jaw; gill opening ventral, anterior duplicate gill membrane present; distance between dorsal fin origin and upper margin of gill opening more than 23.3% HL; both of nostrils with a slim papilla along the anterior margin; 2 rows of white spots on lateral side of head not meeting, but arranged in parallel arched rows..................2 2a. Head about 12.4–12.7% TL........................................... Lamnostoma orientalis (McClelland, 1844)

2b. Head less than 12.4% TL...............................................................................3

3a. Ventral width between gill opening about 6.5–6.9% HL; 2 preopercular pores; 33–41 teeth on lower jaw; lateral white spots on head without hill-shaped papilla, indistinct ventrally...................... Lamnostoma polyophthalmum (Bleeker, 1853)

3b. Ventral width between gill opening about 8.0–9.1% HL; 3 preopercular pores; 47–49 teeth on lower jaw; lateral white spots on head in the form of a series of hill-shaped papilla, all spots distinct.................... Lamnostoma taiwanense sp. nov.