Eremorhax arenarum (Ballesteros & Francke 2007) new combination

Eremocosta arenarum (Ballesteros & Francke 2007): 61–68, figs. 1–6.

Type material. Dunas de Bilbao, Coahuila, México. Male holotype and six paratypes. The male holotype, one “putative” (probably immature female) paratype (Ballesteros & Francke 2 007), an additional male, and one juvenile paratype at IBUNAM; three additional male paratypes are deposited at AMNH. Type examined.

Discussion. Ballesteros & Francke (2007) rightly considered placing E. arenarum in the genus Eremorhax based on the shallow flagellar groove that does not reach the base of the fixed finger (fig. 3, p.65: Ballesteros & Francke 2007). This feature is quite different than the VDC present in all members of the genus Eremocosta males. Ballesteros & Francke (2007) pointed out the similarity of the flagellar groove with other members of the genus Eremorhax as well as the presence of ctenidia, lacking in the genus Eremocosta .