''Xanthodaphne pyriformis'' 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), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

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 ...

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

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 ...

Raphitomidae Raphitomidae is a Family (biology), family of small to medium-sized sea snails, marine (ocean), marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families" ...

Description

The length of the shell attains 7.5 mm, its diameter 3.75 mm. (Original description) The pyriform, ivory-white, thin, fragile shell has an acute

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 ...

. It contains 8

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). In nature File:Photograph and axial plane floral diagra ...

s 8, of which 4 form a light-brown protoconch. They are convex, with remote riblets on the upper part, oblique, and with less stronger ones, which cross each other, in the lower part. The subsequent whorls are scarcely convex, with only a trace of being divided into two parts on the upper two. However, the upper part is marked with elegantly curved, conspicuous riblets, being slightly bead-like just below the suture, on a narrow, infrasutural spiral. The lower part of the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...

shows numerous, faint, spiral striae, becoming stronger on the rather long, slender

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 i ...

. Moreover the lower whorls display elegantly waved growth-lines. 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 oval, wnth a sharp angle above and a narrow gutter-like siphonal canal below, which is directed to the right. The peristome is much broken and probably has a wide, shallow sinus above. The columellar margin shows a very thin layer of enamel, slightly stronger along the siphonal canal. Schepman, 1913. The prosobranchia of the Siboga expedition. Part IV -V - VI: Toxoglossa

Distribution

References

External links

* {{DEFAULTSORT:Xanthodaphne Pyriformis pyriformis Gastropods described in 1913