Maackia is a genus of flowering plants in the legume family, Fabaceae.
 There are about 12 species, all native to eastern Asia, with six endemic to China.
 The generic name honors the botanist Richard Maack.
Aptera is an obsolete taxonomic category, which included the Apterygota along with various other wingless arthropods.
Heterostropha was a previously used taxonomic category, an order of sea snails, within the superorder Heterobranchia.
 In the most current gastropod taxonomy, that of Bouchet & Rocroi, this taxon is no longer in use.
Sigmurethra is a taxonomic category of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs.
 This is an informal group which includes the majority of land snails and slugs.
Cladorhiza segonzaci is a species of sponge in the taxonomic category of Demospongiae.
 The body of the sponge consists of a spicule and fibers and is water absorbent.
Eogastropoda was a previously used taxonomic category of snails or gastropods, a subclass which was erected by Ponder and Lindberg in 1997.
 It was one of two great divisions (subclasses) of the class Gastropoda, the snails.
 The other subclass of gastropods was the Orthogastropoda.
Helleborine is the common name for a number of species of orchid.
 It does not correspond to any currently used taxonomic category.
 Some of the plants called helleborines are classified in the genus "Epipactis", some in genus "Cephalanthera".
 A genus "Helleborine" was formerly recognised but has now been absorbed into the Grass pink genus "Calapogon".
Lithocarpus is a genus in the beech family Fagaceae, differing from "Quercus" in the erect spikes of insect-pollinated male flowers and the short styles with punctate stigmas on the female flowers.
 The World Checklist (see link below) accepts 334 species, though some other texts suggest as few as 100 species.
 About 100 Asian species of the genus were formerly treated in the genus "Pasania".
 All are native to east and southeast Asia.
 These Asian species do not have a well-known English vernacular name, though the generic term stone oak has been proposed.
Gammaridae is a family of amphipods.
 In North America they are included among the folk taxonomic category of "scuds", and otherwise gammarids is usually used as a common name.
Cladorhiza inversa is a species of sponge in the taxonomic category of Demospongiae.
 The body of the sponge consists of a spicule and fibers and is water absorbent.

Question: To which taxonomic category do both Lithocarpus and Maackia belong?
Answer: genus