Two new genera and two new species of the subterranean family Bogidiellidae (Crustacea, Amphipoda) from groundwaters in northern Oman, with notes on the geographic distribution of the family

The bogidiellid amphipod crustaceans Stockigidiella aequimana new genus and species and Omangidiella parvidactyla new genus and species are described from subterranean groundwater habitats in the Sultanate of Oman on the Arabian Peninsula. Stockigidiella is easily distinguished by a row of long, deeply bifid setae on pereopods 5 and 6, whereas Omangidiella is distinguished by a greatly reduced propodus of gnathopod 2 and elongate oostegites; it also possesses a third coxal lobe on the maxilliped, a unique character noted only in three other bogidiellid genera from northern and eastern Africa. At present, the family Bogidiellidae contains 35 genera and 105 species but a significant number of provisionally recognized new species and possibly several new genera await description. The geographic distribution of the family Bogidiellidae is nearly circumglobal, but species tend to be clustered in discontinuous regions. A number of important questions regarding the origin and biogeographic history of the family remains unanswered.