Los Angeles County Wildlife - Terrestrial Gastropods (Snails and Slugs)

Below are data on the terrestrial gastropods (snails and slugs) found in Los Angeles County, including those found only on San Clemente and Santa Catalina Islands.   While not often seen, there are thirty-eight native species (taxa) of native terrestrial gastropods in various natural habitats of Los Angeles County, and another 16 nonnative species.   Some of these gastropods are rare, including taxa endemic to Los Angeles County, such as Glyptostoma gabrielense (San Gabriel Chestnut).
All maps and photos copyrighted by David L. Magney 2004-2009, unless otherwise indicated.
This page created 1 September 2009, and updated 7 September 2009.


Native Land Snails and Slugs

A total of 38 species (including subspecific ranks) of native terrestrial gastropods are known to occur in Los Angeles County, including Santa Catalina and San Clemente Islands. An atlas of the native snails can be seen/downloaded here - Los Angeles County Snail Atlas (5.5 MB PDF), providing details about each taxon and illustrating the counties in California in which they has been reported, with some maps including points indetifying the locations from which they have been collected.   Single maps for each species can be viewed separately below.

Rarity ranking has been established for each taxon based on global and national distribution, population size, and sensitivity by NatureServe, a nonprofit organization with a network of Natural Heritage Programs throughout the nation and internationally.   The Global and National ranking is provided for each taxon (when assigned), and a State ranking if the California Natural Diversity Database has assigned a State rank.   If the CNDDB has not assigned a ranking, one is recommended here.


Anadenulus cockerelli Hemphill 1890, American Keeled Slug - Arionidae Family
This native slug is rare in Los Angeles County.   It is a California endemic, known only from Kern, Los Angeles, Orange, and San Diego Counties.   NatureServe has assigned this taxon a G1G2 rank (Imperiled globally).   The CNDDB has not yet assigned a State ranking for this species.   I recommend a Global ranking of G1 and a California State ranking of S1 (Critically Imperiled statewide).

photo of Anadenulus cockerelli to come Click on map for bigger county distribution map

Catinella rehderi (Pilsbry 1948), Chrome Ambersnail - Succineidae Family
This small snail is fairly common in North America, ranging from Washington and Montana to northwestern Baja California and the Channel Islands.   Catinella rehderi has a fairly short shell with a relatively large conical spire and a rounded-ovate aperture (opening).   It has been given a G3Q rank (Apparently Secure) by NatureServe.   I recommend a California State ranking of S5 (Secure statewide).

photo of Catinella rehderi to come Click on map for bigger county distribution map

Catinella vermeta (Say 1929), Suboval Ambersnail - Succineidae Family
This small snail is common in North America, given a G5N5 rank (Secure) by NatureServe.   It has a fairly short shell with a relatively large conical spire and a rounded-ovate aperture (opening).   I recommend a California State ranking of S5 (Secure statewide).  

photo of Catinella vermeta to come Click on map for bigger county distribution map

Cochlicopa lubrica (Muller 1774), Glossy Pillar Snail - Cionellidae Family
This small snail is common in North America, given a G5N5 rank (Secure) by NatureServe.   I recommend a California State ranking of S5 (Secure statewide).   It has a tall conical shell that is steeply spiraled.   Cochlicopa lubrica has a Holoarctic range.   In North America it ranges from northern Alaska to Chihuahua and Nuevo León, Mexico, from near sea level in boreal & cold-temperate areas to higher elevations (>3,000 m) in western & mountain states; Arizona, California.   In California, it is known from Alameda, Amador, Contra Costa, Los Angeles, Sacramento, San Bernardino, Siskiyou, Tehama, and Ventura Counties, and San Clemente and Santa Catalina Islands.

photo of Cochlicopa lubrica by Shell.Kwanseiac photo of Cochlicopa lubrica by Snails.talesblogspot.com Click on map for bigger county distribution map

Deroceras monentolophus Pilsbry 1944, One-ridge Fieldslug - Agriolimacidae Family
This snail ranges from Seattle, Washington to southern California, known from Los Angeles, Mendocino, Orange, and San Diego Counties.   NatureServe has given this species a G4 rank (Secure globally).   I believe it should be given an S2 (Imperiled statewide) ranking in California.

photo of Deroceras monentolophus to come Click on map for bigger county distribution map

Glyptostoma gabrielense Pilsbry 1948, San Gabriel Chestnut - Megomphicidae Family
This snail is a narrow endemic, known only from Los Angeles County, from the Dominguez Hills (almost certainly extirpated) and Monrovia Canyon on the south slope of the San Gabriel Mountains.   NatureServe has given this species a G2 rank (Imperiled globally).   I recommend a Global ranking of G1 and a California State ranking of S1 (Critically Imperiled statewide).

photo of Haplotrema caelatum to come Click on map for bigger county distribution map

Haplotrema caelatum (Mazÿck 1886), Slotted Lancetooth Snail - Haplotrematidae Family
This snail is known from Santa Barbara, Ventura, Los Angeles, and San Diego Counties, and crossing the border into northwestern Baja California.   Its shell is quite narrow and flat.   NatureServe has given this species a G1N1 rank (Critically Imperiled globally and nationally).   Ventura County Planning Division has placed this snail on its list of locally sensitive species.   I recommend a California State ranking of S1 (Critically Imperiled statewide).

photo of Haplotrema caelatum to come Click on map for bigger county distribution map

Haplotrema calatinense (Hemphill in W.G. Binney 1890), Catalina Lancetooth Snail - Haplotrematidae Family
This snail is a narrow island endemic, known only from Santa Catalina Island.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a California State ranking of S1 (Critically Imperiled statewide).

photo of Haplotrema calatinense to come Click on map for bigger county distribution map

Haplotrema guadalupense Pilsbry 1927, Guadalupe Island Lancetooth Snail - Haplotrematidae Family
This snail is a narrow island endemic, known only from San Clemente Island (Los Angeles County) and Isla Guadelupe (Baja California del Norte, Mexico).   NatureServe has given this species a G2G4 rank.   I recommend a Global rank of G1 and a California State ranking of S1 (Critically Imperiled statewide).

photo of Haplotrema guadalupense to come Click on map for bigger county distribution map

Hawaiia minuscula (A. Binney 1841), Minute Gem Snail - Pristilomatidae Family
This snail is a wide-ranging species in North America from Alaska and Newfoundland south to Central America and the Antilles.   In California it is known from Alameda, Los Angeles, Monterey, Napa, Riverside, San Bernardino, San Diego, San Mateo, and Santa Clara Counties.   NatureServe has given this species a G5 rank.   I recommend a California State ranking of S4 (Apparently Secure statewide).

photo of Haplotrema guadalupense to come Click on map for bigger county distribution map

Helminthoglypta fontiphila Gregg 1931, Soledad Shoulderband Snail - Helminthoglytidae Family
This snail is a narrow endemic of Los Angeles County, known only from Little Rock Creek Canyon on the north flank of the San Gabriel Mountains and Soledad Canyon near Acton.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   The type locality is in Soledad Canyon, the headwaters of the Santa Clara River, hence its common name.

photo of Helminthoglypta fontiphila to come Click on map for bigger county distribution map

Helminthoglypta petricola sangabrielis (Berry 1920), San Gabriel Shoulderband Snail - Helminthoglytidae Family
This snail is a eastern Los Angeles/southwestern San Bernardino County endemic, known from the canyons on the south slope of the San Gabriel Mountains and the western San Bernardino Mountains.   It has been collected from Fish, San Dimas, San Gabriel, and Big Santa Anita Canyons in Los Angeles County and in Ontario (extirpated) and in Millar Canyon of the East Fork of the West Fork Mojave River in the San Bernardino Mountains.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State ranking.

photo of Helminthoglypta petricola sangabrielis to come Click on map for bigger county distribution map

Helminthoglypta petricola zechae (Pilsbry 1916), San Antonio Canyon Shoulderband Snail - Helminthoglytidae Family
This snail is a eastern Los Angeles/southwestern San Bernardino County endemic, known from the canyons on the south slope of the San Gabriel Mountains.   It has been collected from the San Antonio Canyon watershed in eastern Los Angeles County and Cucamonga Canyon, Bear Canyon, Lytle Creek Canyon, Icehouse Canyon, and San Antonio Canyon in San Bernardino County.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State ranking.

photo of Helminthoglypta petricola zechae to come Click on map for bigger county distribution map

Helminthoglypta traskii pacoimensis Gregg 1931, Pacoima Shoulderband Snail - Helminthoglytidae Family
This snail is a western Los Angeles County narrow endemic, known only from Pacoima Canyon on the west slope of the San Gabriel Mountains.   NatureServe has given this subspecies a G1G2T1 rank (Critically Imperiled globally).   I recommend a S1 California State ranking.

photo of Helminthoglypta traskii pacoimensis Click on map for bigger county distribution map

Helminthoglypta traskii traskii Newcomb 1861, Trask or Peninsular Range Shoulderband Snail - Helminthoglytidae Family
This snail is a California endemic, known from Alameda (identity questioned here), Kern, Los Angeles, Orange, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, and Ventura Counties.   It also extends into northern Baja California.   NatureServe has given this species a G1G2T1 rank (Critically Imperiled globally and nationally), and the California Natural Diversity Database has assigned it an S1 rank (Critically imperiled statewide).   Ventura County Planning Division has placed this snail on its list of locally sensitive species.   This snail has been found in the Conejo Valley south of Newbury Park (Thousand Oaks), Ventura County, and has also been observed at Malibu Lagoon State Park in western Los Angeles County.   Its preferred habitat is Coastal Sage Scrub and chaparral.   Trask Shoulderband Snail has been collected from Fort Tejon in the eastern edge of the San Emigdio Range and Temblor Range (Kern County), El Segundo, Hermosa Beach, Los Angeles, Palos Verdes Peninsula, San Fernando Valley, and in Arroyo Seco in Los Angeles County.   It has also been collected from: Reche Canyon in San Bernardino County, Coronado Island, Oceanside, and near San Diego in San Diego County; Oso Flaco Lake in San Luis Obispo County; Santa Anita (Hollister) Ranch in Santa Barbara County; and in the Santa Clara River Valley, Tierra Rejada Valley, and Point Mugu area of the Santa Monica Mountains in Ventura County.

photo of Helminthoglypta traskii traskii
photo of Helminthoglypta traskii traskii photo of Helminthoglypta traskii traskii
photo of Helminthoglypta traskii traskii photo of Helminthoglypta traskii traskii Click on map for bigger county distribution map

Helminthoglypta tudiculata angelena Berry 1938, Southern California Shoulderband Snail - Helminthoglytidae Family
This snail is a southern California endemic, known from the Transverse Ranges of Los Angeles, Riverside, and San Bernardino Counties, and in the Los Angeles Basin (Cerritos).   The shell is helicoid.   The shell is large, reaching 30-40 mm in diameter.   NatureServe has given this species a G2G3 rank (Imperiled globally).   I recommend a G1T1 global rank and a S1 California State rank for this subspecies.

photo of Helminthoglypta tudiculata angelena to come Click on map for bigger county distribution map

Helminthoglypta tudiculata convicta Pilsbry 1913, Southern California Shoulderband Snail - Helminthoglytidae Family
This snail is a southern California endemic, known from the Transverse Ranges of Los Angeles, Orange, San Bernardino and Ventura Counties, in the Los Angeles Basin.   The shell is helicoid; the spire is broadly conic; the inner lip covers half or more of the umbilicus; the lower chamber of penis flars at insertion on the atrium.   The shell is large, reaching 30-40 mm in diameter.   NatureServe has given this species a G2G3N2N3 rank (Imperiled globally and nationally).   Ventura County Planning Division has placed this snail on its list of locally sensitive species.   I recommend a G1T1 global rank and a S1 California State rank.

photo of Helminthoglypta tudiculata convicta Click on map for bigger county distribution map

Helminthoglypta tudiculata imperforata Pilsbry 1939, Southern California Shoulderband Snail - Helminthoglytidae Family
This snail is a southern California endemic, known from the Transverse Ranges of Los Angeles, Riverside, and San Bernardino Counties.   The shell is helicoid.   NatureServe has given this species a G2G3 rank (Imperiled globally).   I recommend a G1T1 global rank and a S1 California State rank for this subspecies.

photo of Helminthoglypta tudiculata imperforata to come Click on map for bigger county distribution map

Helminthoglypta uvasana Roth & Hochberg 1992, Grapevine Shoulderband Snail - Helminthoglytidae Family
This snail is a southern Kern/northwestern Los Angeles County endemic, known only from the type locality (Grapevine Creek, Tejon Ranch) and the Oak Flat Ranger Station in the western edge of the Liebre Mountains.   NatureServe has given this species a G1G2 rank (Critically Imperiled globally).   I recommend a Global rank of G1 and a California State Ranch S1.

photo of Helminthoglypta venturensis by Tom Lawson Click on map for bigger county distribution map

Helminthoglypta vasquezi Roth & Hochberg 1992, Vasquez Shoulderband Snail - Helminthoglytidae Family
This snail is a narrow Los Angeles County endemic, known from the Vasquez Rocks (Type Locality) and Agua Dulce Canyon of the southern part of the Liebre Mountains.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State rank.

photo of Helminthoglypta vasquezi to come Click on map for bigger county distribution map

Herpeteros angelus Gregg 1949, Soledad Desertsnail - Helminthoglytidae Family
This snail is a narrow endemic from the upper Santa Clara River watershed in western Los Angeles County.   It has been collected from Mint Canyon and Soledad.   NatureServe has given this species a G1G2 rank (Critically Imperiled globally).   I recommend a G1 global rank and S1 California State rank.

photo of Herpeteros angelus to come Click on map for bigger county distribution map

Hesperarion hemphilli (W.G. Binney 1875), Hemphill Westernslug - Arionidae Family
This slug is a California endemic from coastal counties, including: Alameda, Los Angeles, Monterey, Orange, San Benito, San Luis Obispo, San Mateo, and Santa Barbara Counties, and Santa Cruz Island.   It has been collected from Mint Canyon and Soledad.   NatureServe has given this species a G2 rank (Imperiled globally).   I recommend a S1 California State rank.

photo of Hesperarion hemphilli to come Click on map for bigger county distribution map

Micrarionta beatula Cockerell 1929, Avalon Islandsnail - Helminthoglytidae Family
This snail is a narrow California island endemic restricted to Santa Catalina Island, Los Angeles County.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State rank.

photo of Micrarionta beatula to come Click on map for bigger county distribution map

Micrarionta gabbii Newcomb 1864, San Clemente Islandsnail - Helminthoglytidae Family
This snail is a narrow California island endemic restricted to San Clemente Island, Los Angeles County.   It has been collected from China Canyon under burned cholla cactus.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State rank.

photo of Micrarionta gabbii to come Click on map for bigger county distribution map

Micrarionta rufocincta (Newcomb 1864), Santa Catalina Islandsnail - Helminthoglytidae Family
This snail is a narrow California island endemic restricted to Santa Catalina and San Clemente Islands, Los Angeles County.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State rank.

photo of Micrarionta rufocincta to come Click on map for bigger county distribution map

Oxyloma sillimani (Bland 1865), Humboldt Ambersnail - Succineidae Family
This snail ranges from eastern Washington to Nevada and California.   In California it is known from Los Angeles, Riverside, San Benito, and Santa Clara Counties.   NatureServe has given this species a G2 rank (Imperiled globally).   I recommend a S2 California State rank.

photo of Oxyloma sillimani to come Click on map for bigger county distribution map

Paralaoma caputspinulae Reeve 1852, Pinhead Spot - Punctidae Family
This snail species is wide-ranging, known from North America from Alaska through Idaho and New Mexico to Jalisco, Mexico.   It is very widespread in temperate regions of the world.   NatureServe has given this species a G5 rank (Secure globally).   I recommend a S5 California State ranking.   This species now includes Paralaoma servilis.

photo of Paralaoma caputspinulae to come Click on map for bigger county distribution map

Pristiloma gabrielinum Berry 1924, San Gabriel Waxy Tightcoil Snail - Pristilomatidae Family
This snail species is endemic to California, known from only three counties: Fresno, Los Angeles, and San Bernardino.   NatureServe has given this species a G1G2 rank (Critically Imperiled globally).   I recommend a G1 global rank and a S1 California State ranking.

photo of Pristiloma gabrielinum to come Click on map for bigger county distribution map

Pristiloma shepardae Hemphill 1892, Island Tightcoil Snail - Pristilomatidae Family
This snail species is a California island endemic, known from only three islands: Santa Catalina, Santa Cruz, and West Anacapa.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State ranking.

photo of Pristiloma shepardae to come Click on map for bigger county distribution map

Punctum californicum Pilsbry 1898, California Ribbed Spot - Punctidae Family
This snail is a wide-ranging western U.S. species, known from most of the coast, Transverse and Peninsular Ranges, and Sierra Nevada, to British Columbia and northern Montana and South Dakota, Colorado, and Arizona.   NatureServe has given this species a G5N5 rank (Secure globally and nationally).   I recommend a S1 California State ranking.   Its shell is very small, to about 1.8 mm, light chestnut brouw and with a shining lustre; spire moderately elevated; whorls convex and about 3.75 in number; periphery rounded; suture deep; protoconch smooth; teleconch with fine, closely sparce axial riblets (bearing very narrow lamellar edges) and with finer axial and spiral striae between; aperture rounded and without denticles; outer lip thin and unexpanded; umbilicus about 20% of the width of the shell   It occurs under sticks, bark, small logs, and loose rocks.

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Punctum minutissimum (I. Lea 1841), Small Spot Snail - Punctidae Family
This snail is a wide-ranging North American species, known from most of the coast, to Canada and New England, and south to Puebla, Mexico.   NatureServe has given this species a G5 rank (Secure globally and nationally).   I recommend a S2 California State ranking.

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Radiocentrum avalonense (Hemphill in Pilsbry 1905), Catalina Mountainsnail - Oreohelicidae Family
This snail is a narrow California island endemic, known only from Santa Catalina Island.   NatureServe has given this species a G1 rank (Critically Imperiled globally).   I recommend a S1 California State rank.

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Sterkia hemphilli Sterki 1890, California Birddrop - Vertiginidae Family
This snail is a California Floristic Provence endemic species, known from Los Angeles (Santa Catalina Island), San Bernardino, San Diego, and San Luis Obispo Counties, and northwestern Baja California.   NatureServe has given this species a G2 rank (Imperiled globally).   I recommend a S1 California State rank.

photo of Sterkia hemphilli to come Click on map for bigger county distribution map

Xerarionta agnesae (Kanakoff 1950), Agnes’ Cactussnail - Helminthoglytidae Family
This snail is a narrow California island endemic, known only from San Clemente Island, and may be an extinct species from the late Pleistocene epoch.   NatureServe has not given this species any rank.   I recommend a GX (Extinct globally) and SX California State rank (Extinct statewide).

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Xerarionta intercisa W.G. Binney 1857, Plain Cactussnail - Helminthoglytidae Family
This snail is a narrow California island endemic, known only from San Clemente Island.   NatureServe has assigned a G1 (Critically Imperiled globally) rank for this species.   I recommend a S1 California State rank (Critically Imperiled statewide) rank for this species.

photo of Xerarionta intercisa to come Click on map for bigger county distribution map

Xerarionta kellettii (Forbes 1850), Catalina Cactussnail - Helminthoglytidae Family
This snail is a narrow California endemic, known only from the tip of the Palos Verdes Peninsula and Santa Catalina Island in Los Angeles County.   NatureServe has assigned a G1 (Critically Imperiled globally) rank for this species.   I recommend a S1 California State rank (Critically Imperiled statewide) rank for this species.

photo of Xerarionta kellettii to come Click on map for bigger county distribution map

Xerarionta redimita (W.G. Binney 1858), Wreathed Cactussnail - Helminthoglytidae Family
This snail is a narrow California island endemic, known only from San Clemente Island in Los Angeles County.   NatureServe has assigned a G1G2 (Critically Imperiled globally) rank for this species.   I recommend a G1 global rank and a S1 California State rank (Critically Imperiled statewide) rank for this species.

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Zonitoides arboreus (Say 1816), Arboreal Glass Snail or Quick Gloss Snail - Gastrodontidae Family
This snail is a wide-ranging North American species, known from much of the coast and Sierra Nevada, south into Central America (Costa Rica).   NatureServe has given this species a G5N5 rank (Secure globally and nationally).   I recommend a S5 California State rank for this species.   Its shell is quite narrow and flat, which is translucent.

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Besides the native snails descussed above, there are ten (10) nonnative terrestrial snails and slugs known to occur in Los Angeles County: Capaea nemoralis, Cecilioides acicula, Deroceras paormitanum, Deroceras reticulatum, Discus rotundatus, Helix aspersa, Lehmannia valentiana, Limax flavus, Limax maximus, Milax gagates, Novisuccinea ovalis, Oxychilus cellarius, Oxychilus draparnaudi, Rumina decollata, Vallonia excentrica, and Vallonia pulchella, none of which are mapped or described here.




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