HYPOCHTHONIIDAE Berlese, 1910 In his early publications Berlese (1896a, 1896b) regarded the genus Hypochthonius as part of the family Nothridae in which it had a separate Position because of the divided notogaster. The genus consisted of species that are now regarded as representatives of separate families, although (with one exception) these still belong to a single group (Enarthronota). Due to the erroneous Observation of a subdivision of the notogaster, Berlese (1896) described also a strongly different species as a Hypochthonius (H. tectorum); this species (afterwards the type of the genus Trhypochthonius) shows, however, little relationship with the Enarthronota. In 1910 (p. 218) Berlese created a family Hypoctonidae (sic!) 3); he divided the genus Hypochthonius, and added other genera so that the family in his opinion consisted of Parhypochthonius, Trhypochthonius, Trizetes, Sphaerochthonius, Cosmochthonius, Hypochthonius (with subgenus Hypochthoniella), and Brachychthonius. Some years after, he gave the same classification (Berlese, 1913a, p. 7). According to moderns views the first-mentioned 2 genera are now classified in groups that are widely remote of the Hypochthoniidae, whilst Trizetes even does not belong to the primitive Oribatid mites. The other ones are all reckoned among the Enarthronota. 3) In the same paper the name is, however, also spelt as Hypochthonidae. Nowadays the genera Hypochthonius, Eohypochthonius, and Malacoangelia only are considered representatives of the family Hypochthoniidae 1). 1) Recently Schweizer (1956, pp. 234-244, figs. 151-159) described a new genus Alphypochthonius with 9 new species, which he classified with the Hypochthoniidae. All species are, however, nymphs and larvae of higher Oribatei, probably Melanozetes, Fuscozetes, Trichoribates, Sphaerozetes, etc. The type of the genus Alphypochthonius is A. alpinus; description and figures of this species strongly resemble Melanozetes nymphs, probably M. mollicomus (cf. Van der Hammen, 1952, p. 97, fig. 8d). Alphypochthonius must therefore be placed in the synonymy of Melanozetes. I remark that the differences in measurements, which Schweizer regards as differences between males and females, are of course due to the presence of different nymphal stages.

Published as part of van der Hammen, L., 1959, Berlese's Primitive Oribatid Mites, pp. 1-93 in Zoologische Verhandelingen 40 on pages 13-14