''Xanthodaphne pyriformis'' is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

of sea snail, a marine gastropod

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 es ...

in the

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

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). . 3 ...

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. Spires are ...

. 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). Whorls in nature File:Photograph and axial plane flo ...

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 whorlshows 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 ...

. Moreover the lower whorls display elegantly waved growth-lines. The

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 ...

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