''Cryptodaphne gradata'' 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 10½ mm, its diameter 4¼ mm. (Original description) The white, fusiform shell is gradate and moderately strong. 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 (the uppermost broken), of which 2 form a reddish-brown

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 calle ...

, with convex whorls (their number probably will have been 4 of which 2 are wanting). The whorls are sculptured by curved riblets, crossed by oblique finer ones in the lower part, which is consequently finely reticulated. The subsequent whorls are convex, angular, gradate by a conspicuous excavation of the upper part, the lower part perpendicular. The spirals consist of a keel and a few, rather strong, slightly flattened lirae on the lower part, 4 in number on penultimate whorl and 2 narrow ones at the base of excavation, just above the keel The body whorl shows numerous stronger, flat lirae, eventually divided by a very fine groove, and some intermediate ones. The axial

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 numerous fine growth striae and curved riblets in the upper part of the excavation, less pronounced on the body whorl, not quite extending to the keel. The body whorl is convex, regularly attenuated towards the rather long

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 ...

. 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 elongate, angular above, ending in a long, gutterlike siphonal canal below. The

peristome Peristome (from the Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mosses In mosses, ...

is broken, probably with a moderately wide, shallow sinus. The columellar margin is concave, with a rather strong layer of enamel along the siphonal canal. Schepman, 1913. The prosobranchia of the Siboga expedition. Part IV -V - VI: Toxoglossa

Distribution

This species occurs in the

Halmahera Sea The Halmahera Sea is a regional sea located in the central eastern part of the Australasian Mediterranean Sea. It is centered at about 1°S and 129°E and is bordered by the Pacific Ocean to the north, Halmahera to the west, Waigeo and West ...

, East Indonesia

References

External links

*
Gastropods.com: ''Cryptodaphne gradata''

Sysoev, A.V. (1996b) ''Deep-sea conoidean gastropods collected by the John Murray Expedition, 1933–34''. Bulletin of the Natural History Museum of London, Zoology, 62, 1–30. page(s): 22
{{DEFAULTSORT:Cryptodaphne Gradata gradata Gastropods described in 1913