Apheloria montana

This large millipede can reach about a gram in weight and can range from 42 mm to 55 mm in length.^[8][5] This species exhibits sexual dimorphism in size, with females generally larger than males. This species is usually black on the dorsal surface with yellow legs and yellow spots on the paranota and another series of yellow spots running down the middle of the back (one in the middle of the collum and one in the middle of each metazonite). In Little Switzerland in Mitchell county in North Carolina, this species features smaller orange spots and orange legs.^[5]

Like most species in the order Polydesmida, this species features 20 segments in adults, counting the collum as the first and the telson as the last. Accordingly, as in most polydesmid species, adult females feature 31 pairs of legs, whereas adult males feature only 30 leg pairs, excluding leg pair 8, which become a pair of gonopods in adult males.^{[12][13][14][5]} As in most species of Apheloria, the distal part of each gonopod (acropodite) in this species is uniformly narrow and curved into a circular shape, and the more proximal part (prefemur) features a projection shaped like a scythe.^[5]

This species can be distinguished from other species of Apheloria, however, based on features of the gonopods. For example, the species A. montana could be confused in the field with its closest relative A. polychroma, which is also found in eastern Tennessee. The junction of the acropodite and the prefemur, however, features a distinct tubercle in A. montana but features an acute angle instead in A. polychroma. Furthermore, the species A. montana can be distinguished from its close relative A. virginiensis, which is also found in North Carolina, based on the shape of the acropodite, which is smoothly circular in A. montana but features a distinct bend like an elbow in A. virginiensis.^[5]

The species A. montana is usually found in mesic habitats such as deciduous forests. This millipede can also be found in habitats with less moisture, such as mixed forests or groves of rhododendron. This species has been found living among pine, maple, oak, beech, tulip poplar, witch hazel, alder, sweetgum, and buckeye. This millipede is usually found under decaying leaves on the forest floor.^[5]

This species feeds on leaf litter but also relies on corpophagy to survive. Millipedes fed leaf litter but deprived of their own feces in a laboratory experiment became inactive and ceased feces production after 21 days, with some millipedes losing weight or dying within a week. The evidence indicates that this millipede does not rely on internal symbionts to process leaf litter and instead relies on bacterial activity in fecal pellets to digest cellulose or possibly to fix nitrogen.^[8]