Species key of Dirivultidae: Stygiopontius.

First, Stygiopontius species can be distinguished by the setation of the 3rd exopodal segment of leg 4 (exo 4, 3rd) (setae are represented by Arabic numbers, spines by Latin numbers). Second, the number of coxal setae (if present, and on which leg it is present) has to be determined (see Figure 1G as an example of a coxal seta). Third, there are some additional characters allowing the final species identification of Stygiopontius. Used abbreviations: antennule (A1), antenna (A2), female (f), male (m), maxilliped (mxp).