Key to the presently known species of Triacanthoneus n. gen.

1. Dorsolateral teeth of carapace situated only slightly anterior and ventral to mediodorsal tooth; orbital teeth present; dorsal spiniform setae of telson small, both situated in posterior half of telson; cheliped ischia with two spiniform setae [Western Atlantic: Gulf of Mexico] .................................................................. Triacanthoneus alacranes n. sp.

- Dorsolateral teeth of carapace situated distinctly anterior and more ventral to mediodorsal tooth; orbital teeth absent; dorsal spiniform setae of telson strong, anterior pair situated in anterior half of telson; cheliped ischia with three spiniform setae ............................................................................................................................................................. 2

2. Major chela with fingers shorter than palm; subapical dent of rostrum directed ventrally; mediodorsal tooth distinctly posterior to mid-length of carapace [Eastern Pacific: Panama, Colombia] ....... Triacanthoneus pacificus n. sp.

- Major chela with fingers longer than palm; subapical dent of rostrum directed anteriorly; mediodorsal tooth slightly posterior to mid-length of carapace [Western Atlantic: Caribbean Sea] ............................... Triacanthoneus toro n. sp.