Nemastomoides is an extinct genus of harvestmen known from the Carboniferous fossil record. The genus is the only member of the family Nemastomoididae and contains three described species. Nemastomoides elaveris was found in the Coal Measures of Commentry in northern France, together with Eotrogulus fayoli. Alexander Petrunkevitch described two fossil harvestmen from Mazon Creek, Illinois, United States, in 1913 in the genus Protopilio, but later synonymized the two with the genus Nemastomoides.