*Folsomia garretti (Bagnall, 1939)
*caeca (Gisin, 1960)
*gisini (Massoud & Rapoport, 1968)
Mucrosomia (formerly Cryptopygus) garretti is a common and probably widespread species with several records from caves, mines and slag heaps. The map includes a few records for Cryptopygus gisini regarded as a junior synonym of Cryptopygus garretti by Potapov (2001) and accepted here. The distinction between Mucrosomia garretti and the cosmopolitan southern hemisphere species Cryptopygus caecus Wahlgren 1906 is minute (details of ventral chaetotaxy).
Cryptopygus garretti is eyeless and has an oval PAO (Fig. 1). It is white and reaches a maximum length of 1.8 mm. The fifth (abd5) and sixth (abd6) abdominal segments are fused. The mucro is unique and has five teeth (Figs. 2, 3). This species appears as Cryptopygus garretti in the AIDGAP key.