Among BC species of Carychium, this is the largest species (mature height to 2.7 mm), further distinguished by its clearly tapering spire and thin, but expanded, palatal lip.
Shell
Minute (mature shell height, 2.0–2.7 mm); growth determinate; rather broadly fusiform, thin-shelled; translucent. Whorls: about 5–5½; spire whorls convex. Spire: elongate; sides usually more-or-less straight; apex bluntly rounded. Suture: deep. Last whorl: not descending at the aperture; no crest. Protoconch: smooth. Teleoconch sculpture: smooth, with weak colabral striae. Periostracum: inconspicuous. Umbilicus: chink-like. Aperture: subovate; ca 1/3 of shell height. Peristome: incomplete. Apertural dentition: 1 (larger) parietal lamella that continues internally around columella a smooth curve; 1 weakly formed lamella at base of columella that may be lacking. Palatal lip: expanded, edge thin, recurved; seldom with a low, medial callus on inside. Peristome, viewed from side: prosocline; more-or-less straight; belly of last whorl not projecting beyond the plane of peristome. Parietal callus: glazed, transparent, inconspicuous. Colour (periostracum): colourless or white; with a slightly silken sheen/shining.
Animal
Body white with dark eyespots.
Habitat
In relatively undisturbed low elevation (≤ 80 m a.s.l.) deciduous and mixedwood forests. Bigleaf Maples are usually present. Colonies are found sporadically in deep litter areas, and nearly always in moist hollows, near seeps or along riparian zones.
Distribution
Global range
BC to northern California where it occurs in the coastal counties of Del Norte, Humboldt and Mendocino (Roth and Sadeghian 2003); east through northern Washington to Idaho (Frest and Johannes 2001).
BC Range
Northern Vancouver Island, British Columbia (Forsyth 2004), south on Vancouver Island, the Gulf Islands, and on the mainland coast to the US border. Currently known in British Columbia from the west side of the Coast and Cascade ranges, it should be expected in the wet southern interior parts of the province. Spotty distribution.
Ecozones
Pacific Maritime; possible for the Montane Cordillera.
Taxonomy
Etymology
Genus name from the Greek, karyx (κάρυξ), "a herald", signifying the ancient use of a shell as a trumpet; the gender is neuter. Latin, "occidentale", "western”.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2024-07-26 4:47:14 PM]
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