Abundant at Monterey. This species is very variable. The surface is usually smooth, but in some specimens it is marked with fine revolving ribs as in C. Pfeifferi. The young and some adults have a rather strong basal rib outside of the umbilical region and bounding it. The umbilicus is either smoothly covered with callus, or a small pit may exist.
The whorls of a variety (fluctuatum, Dall) are marked with oblique, prominent, rounded, short riblets. The shell may be produced, rugged and subcylindrical, or rather depressed and smooth.

Tegula brunnea (Philippi, 1849) (Figure 3) Trochus (Chlorostoma) brunneus Philippi, 1849: 188. Type? Whereabouts unknown (Coan & Kabat 2017). California. Trochus striatulus Kiener, 1850: (this is the volume no.) pl. 33, fig. 3. Chlorostoma brunneum var. fluctuatum Dall, 1871: 130. Type? [Locality not given]. Chlorostoma brunneum var. fluctuosum Dall, 1919: 359. Holotype USNM 60055. Monterey, California. Diagnosis. Shells 20-35 mm, solid with rounded whorls, top often eroded; early whorls with fine spiral striae, later whorls smooth or with weak axial ridges running perpendicular to lip; suture impressed; imperforate, columella with two weak denticles; color russet brown or dark orange. Distribution. Cape Arago, Coos County, Oregon (Belcik 1965), to S of Morro Bay, San Luis Obispo County, on the mainland; extending further south to San Miguel Island (34°N) and San Nicolas Island (33°N), Channel Islands, California. At low tide and in the sublittoral zone to 15 m, often attached to brown algae. Common. Remarks. This species has a relatively short range within the Oregonian faunal province.