A new genus and species of entocytherid ostracod (Ostracoda: Entocytheridae) from the John Day River Basin of Oregon, U. S. A., with a key to genera of the subfamily Entocytherinae Author Weaver, Patricia G. Author Williams, Bronwyn W. text Zootaxa 2017 4273 4 576 586 journal article 32887 10.11646/zootaxa.4273.4.7 69ea9bc8-9500-498e-bc64-cdfc023f82ba 1175-5326 803808 29AE1FBC-1E22-4A3B-B70F-97F0DB1B65D7 Aurumcythere Weaver & Williams , gen. nov. Type species. Aurumcythere tillmani Weaver & Williams , sp. nov. Diagnosis. Carapace subovate to semi-elliptical with eyespot located near anterodorsal margin. Adults with well-developed respiratory plate and masticatory lobes; mandible with six teeth, terminal tooth larger than preceding teeth; antennule consisting of six podomeres; antennae consisting of four podomeres, flexor surface of dorsal apical antennal claw of male setiferous, antennal claws of adult female not conspicuously triunguis, ventral claw without pectinate prominences at base. Legs with short, hook-like terminal claws. Peniferum of adult male short, not extending beyond midpoint of clasping apparatus, without accessory groove or finger guard, distal end of peniferum blunt, with posteroventral hook and spur-like prominences, both curving in an anteroventral direction; spur originating from base of hook. Appendages not sclerotized. Remarks . Aurumcythere gen. nov. differs from all other genera of Entocytherinae in having hook and spurlike prominences at the distal end of its peniferum. Although the peniferum of Psittocythere psitta Hobbs & Walton, 1975 , known from Tennessee , USA, also bears a posteroventral hook, it lacks a spur-like prominence. Further, the entirety of the copulatory complex, including the structure of the hook and shape of the clasping apparatus, is vastly different. The overall shape of both the peniferum and clasping apparatus, and position of the clasping apparatus relative to the peniferum of Aurumcythere gen. nov. most closely resembles that of the notocytherine genus Herpetocythere Hart & Hart 1967, currently known only from Australia . In addition, several Herpetocythere species bear a hook on the distal end of the peniferum, which, although anteroventral, appear similar in structure to the hook found in Aurumcythere gen. nov. Despite several apparent morphological similarities, the presence of a well-developed respiratory lobe and presence of setae on the flexor surface of the dorsal antennal claw of the adult male in Aurumcythere gen. nov. preclude it from being a member of the Notocytherinae . Etymology. Derived from the Latin aurum , meaning gold, as the taxon is known from a historic gold mining district. The suffix -cythere is the usual ending for generic names in the Entocytheridae .