A new spider genus from North America:: Frederickus (Araneae: Linyphiidae)

Frederickus, gen. nov. (Araneae: Linyphiidae: Erigoninae) is described in honor of Dr. Frederick A. Coyle. The genus is diagnosed by the combination of scattered hair-tipped tubercles on the chelicerae, and male palp with a long straight distal suprategular apophysis (DSA) paralleled by the embolic membrane (EM). Two species are included: Frederickus coylei sp. nov. and Frederickus wilburi (Levi and Levi, 1955) comb. nov. transferred from Collinsia (O. Pickard-Cambridge, 1913). Frederickus coylei was previously known as Spirembolus vasingtonus, a nomen nudum. A phylogenetic analysis based on morphology places Frederickus in the "distal erigonines" of Miller and Hormiga (2004). The addition of Frederickus to the character matrix leads to important changes of the relationships within the distal erigonine clade suggesting phylogenetic instability in that clade. Diagnoses, descriptions, locality records, habitat information and distribution maps are given for the two species.