Urochordeuma is a genus of millipedes in the order Chordeumatida and the only genus in the family Urochordeumatidae. Adult millipedes in this family have 30 segments. The two species are known from the U.S. state of Washington, where U. bumpusi is known from Pierce County, and U. porona from King County.
Haplogona is a genus of chordeumatidan millipedes and the only genus in the family Verhoeffiidae. Adult millipedes in this family have 30 segments. These species occur in the southern Alps of Europe, from Genoa, Italy to the Istrian peninsula.
Caseyidae is a family of millipedes in the order Chordeumatida. Adult millipedes in this family have 30 segments. There are about 7 genera and at least 40 described species in Caseyidae.
Cleidogonidae is a family of millipedes in the order Chordeumatida. Adult millipedes in this family have 28, 29, or 30 segments. This family includes the genus Tianella, notable for featuring adult millipedes with 29 segments, a number not found in the adults of any other chordeumatidan species. All Tianella species have adults with 29 segments except for two in which adults have only 28 segments. There are seven genera and at least 140 described species in Cleidogonidae.
Conotylidae is a family of millipedes in the order Chordeumatida. Adult millipedes in this family have 30 segments. There are about 19 genera and at least 60 described species in Conotylidae.
Craspedosomatidae is a family of millipedes in the order Chordeumatida. Most adult millipedes in this family have 30 segments, but some have only 28. There are at least 30 genera and 210 described species in Craspedosomatidae.
Rhiscosomides is a genus of millipedes in the order Chordeumatida with seven described species, and is the only genus in the family Rhiscosomididae. Adult millipedes in this family have 30 segments.
Striariidae is a family of millipedes in the order Chordeumatida. Adult millipedes in this family have 30 segments. There are at least 3 genera and about 13 described species in Striariidae.
Metopidiotrichidae is a family of millipedes in the order Chordeumatida. These millipedes range from 4 mm to 17 mm in length. Adult millipedes in this family have 32 segments, not the 30 segments usually found in this order. Adult males in this family often feature a reduced or vestigial leg pair 10 as part of the gonopod complex, in addition to the two leg pairs typically modified into gonopods in this order. There are about 9 genera and at least 70 described species in Metopidiotrichidae.
Haasiidae is a family of millipedes belonging to the order Chordeumatida. These millipedes range from 4.5 mm to 12 mm in length and are found in Europe. Adult millipedes in this family have 28 or 30 segments.
Apterouridae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 30 segments.
Haaseidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 28 or 30 segments.
Adritylidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 30 segments.
Hoffmaneumatidae is a family of millipedes belonging to the order Chordeumatida. This family includes two genera, one (Hoffmaneuma) found in the Russian Far East and the other (Japanoparvus) found in Japan. Millipedes in this family range from 4 mm to 6 mm in length. Adult millipedes in this family have only 28 segments, not the 30 segments usually found in this order. Adult males in this family feature a reduced leg pair 10 in addition to the two pairs normally modified into gonopods in this order. In the adult male of the species Hoffmaneuma exiguum, for example, the gonopod complex derives from all three leg pairs rather than from just the usual two.
Haplobainosomatidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 30 segments.
Attemsiidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 30 segments.
Trachygonidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 28 or 30 segments.
Lusitaniosomatidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 30 segments.
Heterolatzeliidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 30 segments.
Opisthocheiridae is a family of millipedes belonging to the order Chordeumatida. These millipedes range from 5 mm to 16 mm in length and are found from Belgium to Morocco. Adult millipedes in this family have 26 or 30 segments. This family includes the species Opisthocheiron canayerensis, one of the few species in this order with only 26 segments.
