Vertigo substriata is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of minute air-breathing land snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

, a terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 pulmonate gastropod mollusk or micromollusk

Micromollusk

A micromollusk is a descriptive term for a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also reach adult size at very small...

 in the family Vertiginidae

Vertiginidae

Vertiginidae is a family of minute, air-breathing land snails, terrestrial pulmonate gastropod molluscs or micromollusks in the superfamily Pupilloidea.- Distribution :...

.

Distribution

The type locality is the Barnstaple

Barnstaple

Barnstaple is a town and civil parish in the local government district of North Devon in the county of Devon, England, UK. It lies west southwest of Bristol, north of Plymouth and northwest of the county town of Exeter. The old spelling Barnstable is now obsolete.It is the main town of the...

 district, in Devon

Devon

Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...

shire, England. "Under stones, among dead and decaying leaves and at the roots of grass in woods and moist places."

• Czech Republic
• Netherlands
• Poland
• Slovakia
• Great Britain
• Ireland
• Latvia
• and others

Shell description

The shell

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is oval or subfusiform, rather thin, and semitransparent, glossy, pale yellowish-horn-color, very strongly and obliquely striate and almost ribbed in the line of growth, but less so on the body whorl

Body whorl

Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...

, which is faintly striate spirally, periphery is rounded. The epidermis is rather thick. The shell has 4 whorls

Whorl (mollusc)

A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

, which are very convex or cylindrical, and suddenly increasing in bulk. The
penultimate whorl is slightly exceeding in breadth the last, which occupies about one-half of the shell. Spire

Spire (mollusc)

A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...

 is short, very abrupt and bluntly pointed. Suture is remarkably deep.

Aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is semioval, contracted or sinuous in the middle of the outer edge; teeth from four to six, viz. from one to three (usually two) on the pillar (on parietal wall), one on the pillar lip, and two or three on the inside of the outer lip, the last springing from a white rib; in half grown specimens the pillar lip has a spiral or longitudinal fold. Outer lip thin and slightly reflected, externally strengthened by a strong rib, which is placed very near the opening the mouth; outer edge abruptly inflected, inner lip thickened in the adult. Umbilicus is small and narrow, contracted by a keel or ridge at the base of the shell.

The width of the adult shell is about 0.04 inch, the height is 0.065 inch.

External links

• http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/home/species?id=1679