Abstract. A new dragon millipede species, Hylomus laos, new species is described based on specimens deposited
in the Field Museum of Natural History. The new species can be distinguished from congeners by having antlershaped paraterga; midbody metaterga with two rows of 2+2 spines in anterior row and 3+3 spines in posterior
row; male femora 6 and 7 each with a large ventral tubercle; sternite 5 with a large, sparsely setose trapeziform
lamina between male coxae 4; unmodified epiproct; lamina lateralis of gonopod solenophore broadly rounded,
partly folded to sheath distal part of solenomere. Additional specimens of Hylomus rhinoceros are reported and a
key to all dragon millipede species in Laos is provided.