''Daphnella aulacoessa'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Raphitomidae Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". ''Malacologia'' 47(1-2). . 39 ...

Description

(Original description) The high, narrow, white shell has a fusiform shape. The

whorl 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). Whorls in nature File:Photograph and axial plane floral ...

s are convexly cylindrical. 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. Spires are ...

is high, narrow, subscalar, and conical. The

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

is long, narrow, and conical, with a small snout. The outer lip has a thin crimped edge. The sinus is small, but very well defined at the extreme top of the long narrow

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

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 ...

: Longitudinals—there are on each whorl many (27 on penultimate, about 40 on the body whorl) fine, rounded, curved threads, which correspond with the old lines of growth. They are parted by minute furrows, which are rather narrower than the threads. These longitudinals extend to the base, but not to the snout. Spirals—the riblets are crossed by very similar spiral threads which form minute knots at the crossings, and these are parted by little furrows which are rather wider and less regular than the longitudinal ones, and have occasionally subsidiary threadlets in the middle. There are about 7 of these spirals on the penultimate and about 14 on the body whorl. The sinus-area has very faint threadlets, about three in number, and the first regular spiral below these is stronger than all the rest, and forms a slight keel. They cover the whole snout. The spire is high, conical and subscalar. The apex issmall, sharp, consisting of three (probably, for the extreme tip is broken) embryonic whorls which have the typical ''Defrancia''-sculpture (= '' Pleurotomoides''), the upper third being straight barred and the lower two thirds reticulately barred. But the sculpture is very fine. The shell contains about 8 whorls in all, of regular but rapid increase. They are in form convexly conical, slightly shouldered above. The body whorl, which is narrow, is produced into a convexly conical base and a short oblique-ended snout. The suture is slightly impressed, and is somewhat strongly marked by the swelling of the whorl immediately below. The aperture is narrowly oblong, bluntly pointed above, where it runs out into the small but rather deeply impressed and rounded gutter of the sinus, and produced below into a broadish canal. The outer lip is regularly curved, but at the

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

flattened. The edge forms a regularly curved sweep, prominent in the middle, and retreating into the sinus and siphonal canal. It is slightly contracted, sharp, crimped rather than toothed, thickened a little way within. In the sinus it is blunted and rounded into a gutter. An extension of the outer lip surrounds the sinus and forms a small pad between that and the body whorl. The inner lip shows a very thin glaze on the body and columella. The edge of the columella in front has a very slight oblique bend, and is sharply rounded, but scarce twisted.

Distribution

This marine species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Australia and occurs off

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

References

External links

* {{DEFAULTSORT:Daphnella Aulacoessa aulacoessa Gastropods described in 1881 Gastropods of Australia