Alfenus is a genus of jumping spiders.
The two species were described by Eugène Simon in the early 1900s, based on a single male specimen each. However, the two species are so different that they probably do not belong to the same genus (Szűts & Scharff, 2005).
Alfenus calamistratus has a characteristic hairy appearance.
The males (no females have been observed yet) are 7 (A. chrysophaeus) to 9 millimeters (A. calamistratum) long, with a dark brown carapace. The hairs on A. calamistratum are white or brownish-orange.