in US + Canada:
Dendrolasma - Dendrolasma mirabile, Dendrolasma dentipalpe
Ortholasma - Ortholasma colossus, Ortholasma pictipes, Ortholasma rugosum, Ortholasma levipes, Ortholasma coronadense
Nemastoma bimaculatum (introduced species)
Dendrolasma and Ortholasma have distinctive "cephalic hoods" which extend forward from the carapace. These taxa also have an ornate cuticular sculpturing on the dorsal abdomen.
Pacific States, most Ortholasma restricted to California; O. pictipes northwards to British Columbia
Dendrolasma from far northern California, northwards to Alaska
Nemastoma bimaculatum is apparently introduced from Europe.
Forests, mostly under woody debris
Shear, W.A. & Gruber, J. (1983) The opilionid subfamily Ortholasmatinae (Opiliones, Troguloidea, Nemastomatidae). American Museum Novitates, New York City, no. 2757. (online PDF
Shear, W.A. & Gruber, J. (1987) Ortholasma setulipes
Shear and Gruber is a synonym of Ortholasma coronadense
Cockerell. The Journal of Arachnology, 15(1), 134–135. (online PDF
Shear, W.A. (2010a) New species and records of ortholasmatine harvestmen from México, Honduras, and the western United States (Opiliones, Nemastomatidae, Ortholasmatinae). ZooKeys, 52, 9–45. (online PDF
Shear WA (2016) New Canadian records of Nemastoma bimaculatum
(Fabricius), and a brief summary of introduced Eurasian harvestmen in North America (Arachnida, Opiliones) Zootaxa 4088 (1): 139–140 (online PDF