''Georissa purchasi'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of small

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Hydrocenidae Hydrocenidae is a taxonomic family of minute land snails or cave snails with an operculum, terrestrial gastropod mollusks or micromollusks in the clade Cycloneritimorpha. Hydrocenidae are widespread across the Palearctis and Africa, but reach ...

. The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

is stored in the

Imperial Natural History Museum The Natural History Museum Vienna () is a large natural history museum located in Vienna, Austria. The NHM Vienna is one of the largest museums and non-university research institutions in Austria and an important center of excellence for all matt ...

, Vienna.

Description

The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

is minute, globosely conical, translucid, imperforate (no

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy *Umbilicus (plant), ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus ...

. The

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

consists of very fine growth-striae only. The colour is horny-fuscous. The epidermis is thin and shiny. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

is conical, and rather obtuse. The

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called " ...

is minute, strongly convex, smooth. The shell has 4-5 convex

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagram ...

. The last whorl is slightly greater than one-third of the height of the shell. The base is convex. The suture is impressed. The

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is a little oblique, subcircular. The peristome is simple, straight. The

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

is slightly concave, white. The inner lip is spread over the

, sealing it up more or less completely. The callus on the penultimate whorl unites the margins, and is conspicuous. The width of the shell is 1 mm. The height of the shell is 2 mm. The radula was described by Suter.Suter H. (????). T.N.Z.I., xxiv, 301, pi. 23, f. 58.

Distribution

''Georissa purchasi'' is found in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. * North Island:

Bay of Islands The Bay of Islands is an area on the east coast of the Far North District of the North Island of New Zealand. It is one of the most popular fishing, sailing and tourist destinations in the country, and has been renowned internationally for ...

( Purchas,

Hochstetter Höchstetter (also as Hochstätter or Hochstetter) is a German surname. Notable persons with the surname include: * Astrid Hochstetter (born 1979), German figure skater * Christian Hochstätter (born 1963), German professional footballer * Ferdi ...

);

Waro WARO (94.5 MHz "Arrow 94.5") is a commercial radio station licensed to Naples, Florida, and broadcasting to the Fort Myers-Naples area of Southwest Florida. It is owned by Sun Broadcasting and it airs a classic rock radio format. The studios an ...

;

Whangārei Whangārei () is the northernmost city in New Zealand and the largest settlement of the Northland Region. It is part of the Whangarei District, created in 1989 from the former Whangarei City, Whangarei County and Hikurangi Town councils to admi ...

; vicinity of

Auckland Auckland ( ; ) is a large metropolitan city in the North Island of New Zealand. It has an urban population of about It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and ...

; Wairangi, Waikato Hunua Range;

Mount Pirongia Mount Pirongia is an extinct stratovolcano located in the Waikato region of New Zealand's North Island. It rises to and is the highest peak around the Waikato plains. Pirongia's many peaks are basaltic cones created by successive volcanic erup ...

; Forty-mile Bush. * South Island:

Kenepuru Sound Kenepuru Sound is one of the larger of the Marlborough Sounds in the South Island of New Zealand. The drowned valley is an arm of Pelorus Sound / Te Hoiere, it runs for from the northeast to southwest, joining Pelorus Sound a quarter of the way ...

; Nelson;

Wairoa Gorge Wairoa is the largest town in the Wairoa District and the northernmost town in the Hawke's Bay region of New Zealand's North Island. It is located on the northern shore of Hawke Bay at the mouth of the Wairoa River and to the west of Māhia ...

; Greymouth; Riccarton Bush, near Christchurch.

Habitat

This species is found in native bush in very moist situations, near creeks or swamps, under stones, rotten wood, etc.

References

This article incorporates public domain text from the reference. Suter H. (1913). ''Manual of the New Zealand Mollusca''. Wellington, 1120 pp
page 175
176.

Description

Distribution

Habitat

References

Further reading