Call (1884) referred a specimen, almost certainly this species, from Utah to the genus Ancylus as "Ancylus, sp. undt." Russell (1971) called his Utah specimens, again almost certainly this species, Laevapex californica. Taylor (1986) called Utah specimens Ferrissia californica.
Many authors (e.g., Jones 1935, Jones 1940a, Chamberlin and Roscoe 1948) have referred to the species in Utah by its currently accepted name. Chamberlin and Jones (1929) referred to this species in Utah by its currently recognized name, except for its spelling in the text, where it appeared three times (p 170) as: "Ferrisia [sic] rivularis"; however, this appears to have been either a lapsus or a printer's error, for in their accompanying figure (Fig. 29, p 171) the name was hand-written correctly, and the name appeared correctly spelled in the table of contents (p ix), in their overview of molluscan classification (p 14), and in the index (p 197).
No subspecies are recognized in this species.
Status in Utah
There are 5 known occurrences of this species in Utah, all but 1 being historical. This species has been reported from 4 counties in Utah, all in north-central or west-central parts of the state: Utah County (Call 1884, Chamberlin and Jones 1929, Winger et al. 1972), Morgan County (Jones 1935), Juab County (Russell 1971), and Millard County (Taylor 1986).
Meaningful data regarding abundance of this species in Utah are not available. However, the species is believed to be very uncommon in the state.
Russell (1971) reported remains of what was apparently this species from a spring-fed marsh that had been drained and burned. Similarly, Taylor (1986) found apparently this species, only dead, and noted: "Charred ground and burned bases of sedge clumps show that the marsh has been burned over in the recent past; this is a probable cause for the few live specimens [of mollusks] that were found." Thus, the draining and burning of marsh habitats is a known threat to this species in Utah. Population trend of this species in Utah is not known.
Inventory is needed for this species throughout much of Utah--particularly in the northern and western parts of the state--to determine extent of distribution and abundance.
Habitats Utilized in Utah
No specific habitat data for this species in Utah have been reported. It has twice (Call 1884, Chamberlin and Jones 1929) been reported from Utah Lake, a large, shallow, somewhat saline freshwater lake with numerous springs around its margins. Only one of the two reports, however, provided any detail, that being Call's (1884) report, which stated that the single specimen had been dredged from the lake, thus implying the lake bottom, but Call (1884) did not specify that the specimen was live when collected.
Two Utah studies in which this species was reported (Jones 1935, Winger et al. 1972) dealt with rivers but provided no details.
Two other reports of this species in Utah (Russell 1971, Taylor 1986) were from spring-fed marsh complexes, but the species was not found alive in either study, and thus habitat cannot be known with certainty; Russell (1971) did suggest that "... perhaps, certain of the springs or canals are the habitat ...."