Iowa's Terrestrial Snails

Terrestrial snails are an interesting group. I have to admit that I had a certain ignorance about them. In fact, I did not realize there were significant numbers of terrestrial snails in Iowa until I was an adult. Of course, there is a lack of good guide books that deal with land snails--I am not aware of any that are currently in publication right now.

I have photographed a number of Iowa's terrestrial snails and have located a few sources of information about them. I understand a lot more about them than I used to. However, it still seems that the more I find out about them the more I understand that I don't know. Most of the larger snails, such as this Anguispira alternata (upper right photo) are fairly easy to recognize.

A great number of Iowa's snails are very small--in the range of one to three millimeters in shell length. The differences between some of them are very subtle.

We have a small pad of cement in our yard. I have found several species of snail in that area, sometimes in the open after a rain, and sometimes under pieces of wet wood. It seems that some days there are fairly high numbers and other days there are none. Sometimes the days with many snails seem identical to the days with none. I don't know what causes the difference, and I have searched long and hard to find snails on the days when they don't seem to be present. They must be somewhere but I can't find them.

The photo on the left bottom is Pupoides albilabris.

I have put together a list of Iowa's terrestrial snails, based on searchable museum database records, NatureServe Explorer records, and range maps from Hubricht (1985). By my tentative list, Iowa has 134 species of terrestrial snails.

One thing that might be worth noting is the position of the eyes on these two terrestrial snail species shown. They have two pairs of tentacles, and the eyes are on the very tip of the uppermost pair. Almost all terrestrial species have this arrangement, and none of the aquatic snails do. Most terrestrial snails belong to the order Stylommatophora, which is a group of lung (Pulmonata) snails. Pomatiopsis lapidaria, which is shown on the aquatic snail page is usually considered a terrestrial snail by terrestrial snail experts. It is a gilled snail. One species, Hendersonia occulta is a "Prosobranchia" or gilled snail and is undisputedly a terrestrial snail.

I plan to add pages for a few snails to give a little more in-depth information and possibly some photographs. I do this with the caveat that I am not an expert--I key these things out to the best of my ability. I appreciate feedback from anyone who can point out my errors.

Here is my list of Iowa's terrestrial snails.

order family genus species

Neritopsina Helicinidae Hendersonia occulta (Say, 1831)

Neotaenioglossa Pomatiopsidae Pomatiopsis cincinnatiensis

Pomatiopsis lapidaria (Say, 1817)

Basommatophora Carychiidae Carychium exiguum

Carychium exile exile I. Lea, 1842

Lymnaeidae Fossaria parva Note: aquatic snail found in terrestrial habitats

Stylommatophora Arionidae Arion fasciutus

Limacidae Deroceras agreste (Linnaeus)

Deroceras gracile Rafinesque

Deroceras laeve (O.F. Müller, 1774)

Philomycidae Megapallifera mutabilis (Hubricht, 1951)

Pallifera ohioensis (Sterki, 1908)

Pallifera dorsalis (A. Binney, 1842)

Philomycus carolinianus (Bosc, 1802)

Cionellidae Cochlicopa lubrica (O.F. Müller, 1774)

Cochlicopa lubricella (Rossmässler, 1834)

Cochlicopa morseana Doherty, 1878

Cochlicopa nitens

Discidae Anguispira alternata (Say, 1816)

Angiospira cochi (Pfeiffer)

Discus catskillensis

Discus macclintocki (Baker, 1928)

Discus marmorenosis

Discus patulus (Deshayes, 1830)

Discus shimekii (Pilsbry, 1890)

Discus whitneyi (Newcomb, 1864)

Haplotrematidae Haplotrema concavum (Say, 1821)

Helicarionidae Euconulus fulvus (O.F. Müller, 1774)

Euconulus chersinus

Guppya sterkii (Dall)

Helicodiscidae Helicodiscus natins natins

Helicodiscus parallelus (Say, 1817)

Helicodiscus shimeki Hubricht, 1962

Helicodiscus singleymns

Oreohelicidae Oreohelix strigosa (Gould, 1846)

Oreohelix strigosa cooperi (W.G. Binney, 1858)

Polygyridae Allogona profunda (Say, 1821)

Mesodon clausus clausus (Say, 1821)

Mesodon elevatus

Mesodon thyroidus (Say, 1816)

Mesodon zaletus

Neohelix albolabris (Say, 1817)

Neohelix alleni (Sampson, 1883)

Patera appressa

Patera laevior (Pilsbry, 1940)

Patera pennsylvanica (Green, 1827)

Stenotrema barbatum (Clapp, 1904)

Stenotrema fratermum

Stenotrema hirsutum (Say, 1817)

Stenotrema labrosum

Stenotrema leai

Webbhelix multilineata (Say, 1821)

Xolotrema fosteri (Baker, 1921)

Euchemotrema fraternum fraternum (Say, 1824)

Euchemotrema leai aliciae (Pilsbry, 1893)

Euchemotrema leai leai (A. Binney, 1841)

Punctidae Punctum minutissimum (I. Lea, 1841)

Punctum vitreum (Baker, 1930)

Pupillidae Gastrocopta abbreviata (Sterki, 1909)

Gastrocopta armifera (Say, 1821)

Gastrocopta contracta (Say, 1822)

Gastrocopta corticaria (Say, 1816)

Gastrocopta crestata {cristata?}

Gastrocopta holzingeri (Sterki, 1889)

Gastrocopta pentodon (Say, 1822)

Gastrocopta procera - (Gould, 1840)

Gastrocopta riograndensis

Gastrocopta rogersensis - Nekola and Coles, 2001

Gastrocopta similis - (Sterki, 1909)

Gastrocopta tappaniana (Adams, 1842)

Pupilla blandi

Pupilla muscorum muscorum (Linnaeus, 1758)

Pupoides albilabris (Adams, 1841)

Vertigo binneyana - Sterki, 1890

Vertigo bollesiana - (E.S. Morse, 1865)

Vertigo brierensis - (Leonard, 1972)

Vertigo elatior - Sterki, 1894

Vertigo gouldi

Vertigo hubrichti

Vertigo meramecensis Van Devender, 1979

Vertigo milium (Gould, 1840)

Vertigo modesta - (Say, 1824)

Vertigo occulta

Vertigo ovata Say, 1822

Vertigo pygmaea - (Draparnaud, 1801)

Vertigo tridentata Wolf, 1870

Vertigo ventricosa - (E.S. Morse, 1865)

Columella columella aticola (Ingersoll, 1875)

Columella edentula (Draparnaud, 1805)

Columella simplex

Strobilopsidae Strobilops aeneus Pilsbry, 1926

Strobilops affinis

Strobilops labyrinthicus (Say, 1817)

Succineidae Novisuccinea chittenangoensis - (Pilsbry, 1908)

Novisuccinea ovalis (Say, 1817)

Novisuccinea sp. 3

Novisuccinea sp. 4

Oxyloma haydeni (W.G. Binney, 1858)

Oxyloma retusa (I. Lea, 1834)

Oxyloma retusum (I. Lea, 1834)

Oxyloma sillimani (Bland, 1865)

Succinea avara

Succinea chittenangoensis {found only as a fossil}

Succinea concordialis Gould, 1848

Succinea forsheyi - I.Lea, 1864

Succinea grosvenori I. Lea, 1864

Succinea higginsi Bland

Succinea indiana

Succinea ovalis (Say, 1817)

Succinea retusa

Catinella avara (Say, 1824)

Catinella gelida (Baker, 1927)

Catinella vermeta (Say, 1829)

Catinella wandae - (Webb, 1953)

Valloniidae Vallonia costata (O.F. Müller, 1774)

Vallonia cyclophorella - Sterki, 1892

Vallonia exocentricia

Vallonia gracilicosta Reinhardt, 1883

Vallonia parvula Sterki, 1893

Vallonia perspectiva

Vallonia pulchella (O.F. Müller, 1774)

Zonitidae Glyphyalinia electrina

Glyphyalinia indentata (Say, 1823)

Hawaiia minuscula (A. Binney, 1841)

Mesomphix friabilis (W.G. Binney, 1857)

Nesovitrea binneyana - (E.S. Morse, 1864)

Nesovitrea electrina (Gould, 1841)

Striatura exigua - (Stimpson, 1850)

Striatura milium (Morse, 1859)

Zonitoides arboreus (Say, 1816)

Zonitoides limatulus (A. Binney, 1840)

Zonitoides nitidus (O.F. Müller, 1774)

Mesomphix inornatus (Say)