Species of Californiulus exhibit two major color patterns. Some are characterized by a broad stripe of light brown, orange or yellow extending down the dorsal surface, while others are banded in light brown against a dark gray or black base color. Adult individuals range from 5 to 11 cm (2 to 4.5 in) long and up to 4.7 mm wide.[1]
The constituent species of Californiulus range from northern Washington south to Death Valley, California, and one species occurs separate from the others in a range from extreme eastern Oregon to Montana.
^Shelley, Rowland M. (1994). "Revision of the milliped family Paeromopodidae, and elevation of the Aprosphylosomatinae to family status (Julida: Paeromopodoidea)". Entomologica Scandinavica. 25 (2): 169–214. doi:10.1163/187631294X00298.
^Hoffman, R. L. (1999). "Checklist of the millipeds of North and Middle America". Virginia Museum of Natural History Special Publications. 8: 1–553.
^Shelley, R. M. & Bauer, S. B. (1997). "New records and species, and taxonomic alterations in the milliped family Paeromopodidae (Julida)". Entomological News. 108 (1): 1–14.
