Achatinella byronii 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 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 in the family Achatinellidae

Achatinellidae

Achatinellidae is a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Achatinelloidea.- Taxonomy :...

. This species is endemic to the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.

Achatinella byronii is the type species of the subgenus Bulimella.

Shell description

The dextral or sinistral 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 imperforate and pyramidal-conic; solid and glossy with an obtuse apex

Apex (mollusc)

Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...

. The shell has 6.5 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...

. Shell color varies, but is typically green and light greenish-yellow in oblique streaks on the last two whorls, with a faint green peripheral band and a dark chestnut band bordering the suture below. The preceding whorl is yellow with a chestnut band and the three embryonic whorls

Protoconch

A protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...

 are pinkish gray. The 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 white and the lip is bordered with dark brown. Faint spiral striae sculpture

Sculpture (mollusc)

The sculpture of a mollusc shell is the three-dimensional ornamentation on the outer surface, as distinct from the basic shape of the shell itself or colouration. Sculpture may be concave as well as convex. Sometimes it has microscopic detail. Sculpture refers to the calcareous outer layer, not the...

the embryonic whorls, and later whorls are convex and irregularly wrinkled in the direction of growth-lines. The whorls are convex and the last is often very obtusely angular at the periphery. The aperture is strongly oblique and the lip thickened within by a strong rib near the margin. The columellar fold is moderate, and white or tinted.

The height of the shell is 20.0 mm. The width of the shell is 11.0 mm.

External links

• http://hbmp.hawaii.edu/hbmp/printpage.asp?spp=IMGASN7060