Geophilus

This genus is characterized by a claw-shaped ultimate pretarsus, complete or nearly complete coxo-pleural sutures at the prosternum, and incomplete chitin-lines.^[6] Centipedes in this genus feature slightly elongate heads and labral intermediate parts with tubercles, the forcipules are usually poorly elongate with a single small tubercle at the base of each tarsungulum, and the anterior trunk metasternites usually have an anterior medial socket and a posterior transversally elongate pore-field.^[5]

Centipedes in this genus range from about 1 cm to about 8 cm in length.^[5] Several species in this genus are notable for their small sizes, including G. minimus (measuring 9.5 mm in length),^[7] G. pinivagus (10 mm),^[7] G. richardi (10 mm),^[8] G. pusillus (11 mm),^[7] and G. piae (11 mm).^[9] Other species are notable for their large sizes, including G. procerus (measuring 72 mm in length)^[7] and G. piedus (75 mm).^[10]

Although centipedes in this genus can have as many as 89 pairs of legs (in G. caucasicus,^[11] with 57 to 89 leg pairs^[12]), most species in this genus have a much smaller number of legs.^[2] For example, two species in this genus include centipedes with only 29 leg pairs, the lowest number recorded in the family Geophilidae: G. persephones (29 in the only specimen, a male) and G. richardi (29 or 31 in males and 33 in females).^[13] Several other species in this genus are known from specimens with notably few leg pairs in each sex, including G. ribauti (as few as 31 in males and 33 in females),^[14] G. hadesi (33 in both sexes),^[8] G. piae (as few as 35 in males and 37 in females),^[15] and G. bipartitus (35 in males and 39 in females).^[16]

This genus is the largest in the family Geophilidae, with about 140 species:^[5][1][3]