In the New World, the milliped family Platyrhacidae (Polydesmida) is known or projected for Central America south of
southeastern Nicaragua and the northern ¼ of South America, with disjunct, insular populations on Hispaniola (Haiti),
Guadeloupe (Basse-Terre), and St. Lucia. Male near-topotypes enable redescription of Proaspis aitia Loomis, 1941,
possibly endemic to the western end of the southern Haitian peninsula. The tibiotarsus of its biramous gonopodal
telopodite bends strongly laterad, and the medially directed solenomere arises at midlength proximal to the bend. With a
uniramous telopodite, P. sahlii Jeekel, 1980, on Guadeloupe, is not congeneric, and Hoffmanorhacus, n. gen., is erected
to accommodate it. Nannorrhacus luciae (Pocock, 1894), on St. Lucia, is redescribed; also with a biramous telopodite, its
tibiotarsus arises distad and diverges from the coaxial solenomere. The Antillean species do not comprise a clade and are
only distantly related; rather than introductions, they plausibly reflect ancestral occurrences on the “proto-Antillean”
terrain before it rifted from “proto-South America” in the Cretaceous/Paleocene, with fragmentation isolating modern
forms on their present islands. Existing platyrhacid tribes are formally elevated to subfamilies as this category was omitted
from recent taxonomies. Without unequivocal evidence to the contrary, geographically anomalous species should initially
be regarded as indigenous rather than anthropochoric.
