Colobognathans
Guides
Hirudisomatidae
Hirudisomatidae is a family of colobognathan millipedes in the order Polyzoniida, comprising approximately 20 species across seven genera. The family exhibits a disjunct distribution spanning Eurasia from Spain to the Himalayas, Japan, and western North America from southwest Canada to central Mexico. Members of this family possess characteristic colobognathan features including reduced mouthparts and a simplified head structure. The family contains two genera in the Western Hemisphere (Octoglena and Mexiconium) with seven species, while the remaining five genera occur in the Eastern Hemisphere.