Revision of the genus Xiphocephalus and description of Xiphocephalus ellisi n. sp. (Apicomplexa: Eugregarinida: Stylocephalidae) from Eleodes opacus (Coleoptera: Tenebrionidae) in the western Nebraska Sandhills

Xiphocephalus is revised, clarifying diagnosis of the epimerite complex, gametocyst, and oocyst. Xiphocephalus ellisi n. sp. (Apicomplexa: Eugregarinida) is described from Eleodes opacus (Coleoptera: Tenebrionidae) collected from Keith County in the Sandhills of western Nebraska. Measurements are means in micrometers. Developing trophozoites solitary; epimerite a complex of terminal epimerite and intercalating diamerite: epimerite elongate, ensiform, with transverse basal tumidus, length 2-3 times width of basal tumidus; width approximately half that of basal tumidus; tumidus toroidal, concavoconcave in anterioposterior axis: diamerite roughly cylindrical, no longitudinal fold apparent, length approximately twice width. Association late, frontal, isogamontic. Protomerite depressed ovoid, length 84.1, width 114.9, anterior distance to widest point 50.8. Protomerite-deutomerite septum clearly marked and constricted, width 99.3. Deutomerite narrowly obovoid, length 1,094.0, maximum width 197.0, anterior distance to widest point 137.8, equatorial width 163.3. Total length 1,204.4. Nucleus ellipsoid, length 64.9, width 42.2; typically with 2-3 polysomal endosomes. Gametocysts roughly spherical, length 376.1, width 348.2, wall paperlike, papillated, dehiscing by simple rupture, releasing oocysts in coiled chains, epispore packet absent, gametocyst residuum present. Oocysts brown to black, broadly deltoid, gibbous in lateral aspect, slightly keeled in dorsal aspect, length 9.7, height 8.5; with terminal protuberances and a single, central, spherical residuum.