The Website for Houston Mollusks
Your Subtitle Text
Terrestrial Snails

  Asian Tramp Snail, Bradybaena similaris (Férussac, 1821).
  Size: 15mm diameter, 9- 11mm tall
  Origin: Southeast Asia
  Distribution: Southeast United States
  Description: The shell is round with 5 whorls, and is polymorphic: brown or yellow, usually with a dark band running up the whorls tangent to the shoulder.
  Distinguishing Features: Perforate, reflected.

  This snail can be either white, tan, or brown, and usually has a dark band.


Whitewashed Rabdotus, Rabdotus dealbatus (Say, 1830). 


 Size25mm tall (shell)


 Distribution: Southwest United States

 Confirmed Location(s):  San Marcos River

 Habitat:  unknown  
 Description Tall, conical shell with 5-6 whorls. Pale color with faint stripes.

Striped Rabdotus, Rabdotus alternatus (Say, 1830). 


 Size25mm tall (shell)


 Distribution: Southwest United States

 Confirmed Location(s):  Kerrville, San Marcos River

 Habitat:  prairie conditions, riverbanks

 DescriptionThis shell is usually opaque pale white with faint stripes.


Marie's* Rabdotus, Rabdotus alternatus mariae (Albers, 1850). 


 Size25mm tall (shell)


 Distribution: Southwest United States

 Confirmed Location(s):  Kerrville, San Marcos River

 Habitat:  prairie conditions, mesquite forests

 DescriptionThis rabdotus is usually pale white.  

 *Assumed name



Southeastern Tigersnail, Anguispira strongylodes (Pfeiffer, 1854).


Size:  25mm diameter, (shell).

Origin: Native

Distribution: Southeast United States

Confirmed Location(s):   Brazos County
Habitat: Forest, wooded areas.
Description:  A round, disc-shaped shell with lateral grooves and a rough texture. It is tan or cream-colored with reddish-brown flecks and dashes, hence the name "tigersnail." 



 Brown Garden Snail, Cornu aspersum* (Müller, 1774). 

Size:  25-38 mm in diameter (shell)

Origin: Southeastern Europe, Turkey
DistributionNorth America

Confirmed Location(s): Harris County
Habitat: gardens, broad-leafs, decks
: The globular shell is brown or tawny with dark bands with light flecks.  The surface is finely wrinkled and covered with a film-like periostracum that tends to flake off with age. 

Distinguishing Features: Imperforate, reflected, white lip.

Formerly known as Helix Aspersa



Chocolate-Band Snail, Eobania vermiculata (Müller, 1774). 


 Size 25mm diameter, 15mm tall (shell).

 Origin Europe

 Distribution: Southwest United States

 Confirmed Location(s):  Harris County

 Habitat:  unknown 

 Description  The shell is subglobose, with a down-faced aperture.  multiple brown bands adorn the shell, which blend in and blur as they near the apex.  The body has a dark gray mantle and dorsal side, and a pale yellow ventral.

Distinguishing Features: Imperforate, reflected, uniformly light mouth.



Milk Snail, Otala lactea (Müller, 1774). 

:  28 mm diameter, 17 mm height 
Origin: Europe
Distribution: West Texas, Harris County
Confirmed Location(s): Houston, Kerrville
Habitat: gardens, shrubs, heavy vegetation 
Description: The shell is milky white or cream colored, often with faint bands and fleck marks. Some forms have bold brown lateral bands and stripes.
Distinguishing Features: Imperforate, reflected, uniformly dark mouth. 

This snail was once known as the Spanish Edible Snail.

Watch a Video of O. lactea




Globular Drop, Olygyra orbiculata (Say, 1818). 


 Size 8mm diameter, 8mm tall (shell)

 Origin native
 DistributionSoutheast United States
 Confirmed Location(s):  Harris County, Lake Livingston

 Habitat:  soil, leaf detritus, bushes, areas near water

 Description Very round, spherical shell, sometimes with a light band encircling the whorls. Colors range from red, orange, yellow and white to brown, grey, and greenish. The eyes are located directly on the body, not within eyestalks. It has two tentacles, as well as an operculum. 

This snail is usually found near lakes, rivers, and bayous.

Learn more about Olygyra orbiculata




Evening Fieldslug, Deroceras laeve (Müller, 1774). 

25-40mm long

Distribution: unknown 
Confirmed Location(s): Harris County
Habitat: Leaf detritus, rotting wood, soil, under flat surfaces.
This slug is usually some form of grey or brown. The head can stretch out very far from the shield.

The Evening Fieldslug comes out at dusk to search for food.


Yellow Garden Slug, Limax flavus (Linnaeus, 1758). 

 Size: 60- 100mm long 

 Origin: Europe                                          

 Distribution: worldwide

 Confirmed Location(s):  Harris County

 Habitat: Wherever people are... (Houses, porches, siding, gardens, etc.); Leaf detritus, rotting wood, mulch, soil, under wood, water meters.

 Description: This mollusk has a slick, scaly-looking skin that is usually grayish-green with speckled patterns. The underside is yellow. 

This large slug likes to sleep during the day (like the one pictured), and comes out at night to look for food. Upon being touched, it secretes a thick layer of slime which is nearly impossible to wash off.

This species is used in the medical field for research involving neurotoxins. (see









Banded Scrubsnail, Praticolella berlandieriana (Moricand, 1833).


Size: 10mm diameter, 8mm tall (shell).

Origin: Native

Distribution: Texas

Confirmed Location(s): Manvel, Industry
Habitat: Prairie, Mesquite.
Description:  A round, pale shell, usually with a faint band running along the side.  The lip is squared at the shoulder and curls in tightly to meet the shell.  

Distinguishing Features: Perforate, squared aperture, reflected lip.

The Banded Scrubsnail was once known as "Berlandier's Praticolelle" (Abbott, pg. 135). 


Vagrant Scrubsnail, Praticolella griseola (Pfeiffer, 1841).


Size:  12mm diameter (shell).

Origin: Native

Distribution: Southeast United States

Confirmed Location(s):  Industry, TX; Austin County
Habitat: Prairie conditions, mesquite
Description: The shell is round and translucent. The color is gray with dark bands and flecked patterning.

Distinguishing Features: Perforate, reflected.


Texas ThreetoothTriodopsis vultuosa (Gould, 1848).


Size: 12mm diameter (shell).

Origin: Native

Distribution: Texas

Confirmed Location(s): Texas   
Habitat: dead wood, dead leafs, detritus, dirt & soil; under wood.
Description: Circular, ribbed shell, brown periostracum. The parietal tooth is wedge-like rather than V-shaped.

Distinguishing Features: Perforate, reflected, 2 lip teeth, one parietal tooth.


Grassland LiptoothMillerelix mooreana (Binney, 1858).


Size: 10mm diameter (shell).

Origin: Native

Distribution: Texas

Confirmed Location(s): Texas  
Habitat: dead wood, dead leafs, detritus, dirt & soil; under wood.
Description: Circular, short shell, usually tan, brown, or yellow-colored.  

Distinguishing Features: Perforate, reflected.

 This species is practically indistinguishable from the 

 Texas LiptoothLinisa texasiana (Moricand, 1833).

Southern Flatcoil, Polygyra cereolus (Mühlfeld, 1816).


Size:  8mm diameter, 3mm tall (shell).

Origin: Native

Distribution: Southeast United States

Confirmed Location(s):  Everywhere
Habitat: dead wood, gardens, shrubs, sides & bases of structures, dirt, soil, bushes.
Description:  Round, flat shell, usually brown with dark flecks and fine grooves, like a rope. The aperture is round with a single tooth, and the umbilicus is very obvious. Live specimens are often a ruddy orange color.

Distinguishing Features: Perforate, reflected.

This is possibly the most common snail species in Texas.

White-lip Globe, Mesodon thyroidus (Say, 1817).


Size:  28mm diameter (shell).

Origin: Native

Distribution: Southeast United States

Confirmed Location(s): Kerrville, San Marcos River 
Habitat: Prairie conditions, wooded areas, creek beds.
Description:  Round, subglobose shell. The surface is usually yellowish-tan and finely ribbed.

Distinguishing Features: Perforate, reflected, single parietal tooth. 

NOTE: An opaque periostracum (as pictured at left) is unusual.  A more typical coloration for this species would more closely resemble that of M clausus (see below).


photo by Guido Poppe.  Used with permission.

Yellow Globelet, Mesodon clausus (Say, 1821).


Size:  25mm diameter (shell).

Origin: Native

Distribution: Southeast United States

Confirmed Location(s):  San Jacinto County
Habitat: Forest, wooded areas, near water.
Description:  Round, subglobose shell. The surface is translucent and is finely ribbed.

Distinguishing Features: Perforate, reflected, NO parietal tooth. 





Texas Oval, Patera roemeri (Pfeiffer, 1848).


Size:  25mm diameter (shell).

Origin: Native

Distribution: Southeast United States

Confirmed Location(s):  Kerrville, San Marcos River
Habitat: Forest, prairie, near water.
Description: Round, flat, subglobose shell. The surface is tan and fairly smooth.  The parietal tooth is usually present but often missing.

Distinguishing Features: Imperforate, reflected, single parietal tooth.

Lowland Pillsnail, Euchemotrema leai aliciae (A. Binney, 1841).


Size:  13mm diameter (shell).

Origin: Native

Distribution: Southeast United States

Confirmed Location(s):  Montgomery County, Brazos County

Habitat: Forest, wooded areas, near water.

Description: Round shell, usually brown and slightly covered in tiny bumps and hairs. The aperture has a single long tooth.
Distinguishing Features: Fuzzy periostracum, perforate, irregular lip, oversized parietal tooth.


  Rosy WolfsnailEuglandina rosea  (Férussac, 1821). 


  Size: 4-6 cm long (shell); 10 cm long (body).

  Origin: Southeastern United States, Texas & Florida

  Distribution: Southeastern United States; Introduced into Hawaii.

  Confirmed Location(s)Harris County


  Description: Conical shell, pinkish-brown or orange in color w/ lateral grooves.   

  Distinguishing Features: Conical, imperforate, NOT reflected.

 This is a fascinating Texas snail. It is a predator and actively hunts smaller  snails.   


  Learn more about Euglandina rosea

  Watch a Video of E.rosea


  Two-tone GulellaHuttonella bicolor (Hutton, 1834). 

 Size 7mm tall (shell)

 Origin unknown (exotic)

 Confirmed Location(s):  garden, Harris County

 Habitat:  soil, leaf detritus

 Description Very small, translucent shell. The tops of the whorls appear serrated, like a knife's  edge. The top is blunt, and the lip has multiple teeth when fully developed. The shell has an opal-  like sheen. The body is bright yellow and red.

 Distinguishing Features: Multiple aperture teeth. 

 This snail is a predator, feeding exclusively on other snails. It prefers to eat Allopeas gracile,  another exotic species about the same size.


Graceful Awlsnail
, Allopeas gracile (Hutton, 1834). 


 Size12mm tall (shell)

 Originunknown (exotic)

 Distribution: Worldwide

 Confirmed Location(s)Harris County, Industry, San Marcos River

 Habitat:  unknown

 Description Tall, conical shell with 7-9 whorls whorls. Pale color with faint stripes. Live specimens are bright yellow and violet.

 Distinguishing Features: conical, perforate, NOT reflected.

Decollate Snail, Rumina decollata  (Linnaeus, 1758). 


 Size25-40mm tall (shell)

 Origin:  Mediterranean region

 Distribution: West Texas

 Confirmed Location(s):  Kerrville, San Antonio, Waco, San Marcos.

 Habitat:  prairie conditions, riverbanks

 DescriptionThis snail loses its apex, resulting in a broken look. This also affects the overall height of the shell. The shell is usually brown or tan, and the body is gray.

 Distinguishing Features: Perforate, NOT reflected, missing apex.

This species is carnivorous and eats other snails. It has been used to control populations of the destructive
Helix aspersa, which devastates citrus crops in California.

R. decollata has been naturalized to Texas. It has been bred here especially to serve as a predator to pest species. The effort has been very successful.


 Genii: Succinea & Oxyloma


 Size:  5-15mm tall (shell)

 Origin:  unknown (probably native)

 Distribution: unknown

 Confirmed Location(s):  Harris County, Montgomery County, Kerrville, San Marcos 

 Habitat:  near fresh water

 Description Small, extremely thin & fragile shell, very large aperture. Shells are pale and  translucent with occasional stripes.   
There are many species of Texas amber snails. We are in the process of determining their ID's.  

Ambersnails live closer to the water than any other kind of land snail.


 Black-Velvet LeatherleafBelocaulus angustipes, (Heynemann, 1885).

 Size: 50+ mm long.

 Origin: unknown (exotic)                                           


 Confirmed Location(s) HBU campus, Harris County

 Habitat: Leaf detritus, under rocks and wood.

 Description: The skin looks like velvet, but slimes to the touch. .  The dorsal side is black, the ventral is tan.

Black-Velvet Leatherleafs are mysterious in the way they're found:  Many specimens can be located at a certain time and place, then disappear almost overnight. There is no logical pattern in the way they appear. 



Perforate DomeVentridens demissus (Binney, 1847). 


 Size 10- 12mm diameter, 5- 7mm tall

 Origin native
 DistributionSoutheast United States
 Confirmed Location(s):  Harris County, Lake Livingston

 Habitat:  soil, leaf detritus, bushes, areas near water

 Description Circular shell, very smooth surface.  Slick to the touch. There is often a pale slash on the ventral side near the aperture.  Some specimens have black on the dorsal.

 Distinguishing Features: Perforate, NOT reflected  

This species is one of the most common snail in Texas.


 For a complete list of land snails from Houston, click here.
Website Builder