Description. Shell of moderate size, smooth or with sculpture of weak to strong divaricating ribs. Apex close to posterior margin, protoconch with tip immersed, early teleoconch with fine spiral sculpture through shell diameter of 1.3 mm, at this diameter there is a resting stage; subsequent growth smooth. Coarse rugose sculpture of some specimens emerging at later growth stage. Deck attached half length on right side. Length 10-26 mm.
Type Locality and Type Specimens. Victoria, Vancouver Island, British Columbia, 60 fathoms. Holotype: USNM 31100. Verticumbo charybdis was described from the middle Pleistocene Timms Point Silt, San Pedro, California. Paratypes are at the SBMNH, but the location of the holotype is unknown. Material Examined. Santa Maria Basin, Phase I, sta. 13, 197 m (5); sta. 16, 591 m (1). Other material examined: 3 lots in LACM collection.

Distribution. Bering Sea, Alaska (Dall, 1921), to San Diego, California (33°N).
Habitat 100-2100 m, attached to shells or other hard substrata. This is the only calyptraeid in the northeastern Pacific known from abyssal depths [LACM 64-109, from the Cascadia Abyssal Plain, Oregon, 2086 m]. It is an uncommon species in collections, owing to its deep-water habitat.
Remarks. This differs from Crepipatella dorsata in the presence of rugose sculpture (although not in all specimens) and in having a larger spiral phase of the early teleoconch and a less deeply detached deck on the right side.

Dall's holotype of C. orbiculata was smooth-shelled and the apical area is worn. Berry (1940) noted sculptured and smooth forms in the Pleistocene species he described as Verticumbo charybdis. Woodring (1946) reported Berry's species to be living off southern California and compared the morphology of the deck to that of Dall's species. Here I synonymize the two taxa and note that the Recent material also vanes from smooth to strongly sculptured.
This species is the type species and only known member of the subgenus Verticumbo Berry, 1940, which is distinguished by its relatively large early teleoconch with fine, sharp spiral cords through a shell diameter of 1.3 mm. Hoagland (1977:374) did not have sufficient material to determine the status of Verticumbo.