Shell rather small, depressed, umbilicate, body whorl ornamented by about 12 to 13 spiral ribs with fine spiral ribs in the interspaces; the ribs above the widest part of the whorl are coarser and noded rather than smooth. Altitude, 5.8 mm.; width of body whorl, 7.8 mm.
Holotype, Na 5487 (C.A.S. type coll.), from Locality 754 (C.A.S.), Magdalena Bay, Lower California; G. D. Hanna and E. K. Jordan, collectors; Pleistocene.
The depressed spire and the much heavier, noded spiral ribs on the upper portion of the whorls distinguish the present species from Tegula globula (Carpenter) and T. impressa (Jonas).

Tegula eiseni Jordan, 1936 (Figures 9-10) Tegula eiseni Jordan, 1936: 161, pl. 17, figs 3-5. CASG 5487.00. Magdalena Bay, Baja California, Pleistocene. Tegula (Agathistoma) mendella McLean, 1964: 131, pl. 254, figs 5-6 [retracted, p. 133] Holotype USNM 636090. Mission Bay, San Diego. Diagnosis. Shell small, thick; whorls evenly rounded; sculpture of strong to weak nodular spiral cords; base with more or less nodulose, broad spiral ridges becoming smooth towards the aperture; lip lirate within; umbilicus wide, with a spiral ridge inside; color dark brown to blackish with alternating light and dark markings on the spiral cords, umbilical area white. Height 20-25 mm. Distribution. Los Angeles County, California (34° N) to Punta Entrada, Magdalena Bay, Baja California (25° N). Common at low tide and in the sublittoral zone on rocks to 20 m. Remarks. This species had long been known as Tegula ligulata (Menke, 1850), but that name applies to an uncommon, related species from Mazatlan, Mexico.