In this volume of the Synopses on Palaearctic Collembola, we describe the entire family Hypogastruridae except for the monospeciﬁc genus Gulgastrura reticulosa Yosii, 1966a from Korea, which was elevated to the rank of family: Gulgastmridae Lee & Thibaud, 1998.
As “Palaearctic species”, We included species from the arctic as well as from the Chinese-Japanese and Nepalese region. “Nearctic species” are described as inhabitants of North America including Mexico as a borderregion between Nearctic and Neotropic regions. In the keys to Holarctic genera and species, the territories of occurrence are indicated for species living outside the Palaearctic region.
The introduction, general description, key to the genera of the world as well as the keys and diagnoses of the genera Acherongia, Acherontides, Acherontiella, Acheroxenylla, Bonetogastrura, Denigastrura, Jacutogastrura, Mesachorutes, Mesogastrura, Microgastrura, Ongulogastrura, Orogastrura, Pseudacherontides, Schaefferia, Typhlogastrura, Willemia, and Xenyllogastrura were written by Jean-Marc Thibaud, who also carried out the general revision and standardised the entire text.
The keys and diagnoses of the genera of Hypogastruridae with eight eyes, i.e. Ceratophysella, Choreulinula, Hypogastrura, Mitchellania, Mucrella, Schoettella, and Triacanthella were produced by Hans-Jürgen Schulz. Finally, Maria Manuela da Gama Assalino wrote the descriptions of the genera Paraxenylla and Xenylla. Data available up to the end of 2003 were taken into consideration.