''Menestho felix '' 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 ...
Pyramidellidae
Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs. The great majority of species of pyrams are micr ...
, the pyrams and their allies.
[Dall & Bartsch, ''Notes on Japanese, Indo-Pacific and American Pyramidellidae''; Proceedings of the U.S. National Museum, vol XXX n° 1452; 1906]
Description
The broadly elongated conic shell is turreted and subdiaphanous. It measures approximately 2.6 mm. The
whorls of 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 calle ...
are small, almost completely obliquely immersed and only a part of the last rounded volution is visible above the first of the later whorls. The 5½ whorls of the
teleoconch
The gastropod shell is part of the body of a gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. So ...
are somewhat inflated, well rounded and moderately shouldered. They are marked by strong, equally developed, spiral keels which are separated by subequal, deep, rounded sulci. The latter are somewhat broader than the keels and crossed by many slender raised axial threads. Three keels appear partly upon the first and second, on the third and fourth
suture, but the greater part of it is covered up by the summit of the succeeding volution. The penultimate whorl has four keels, the posterior one of which marks the summit and is a little wider than the rest and somewhat flattened. The periphery of the
body whorl is marked by a sulcus. The base of the shell is well rounded and attenuated. It is ornamented like the spaces between the sutures, having six spiral keels. These keels, as well as the sulci, gradually diminish in breadth from the periphery to the
umbilical
Umbilical may refer to:
*Umbilical cable
*Umbilical cord
*Umbilical fold
*Umbilical hernia
*Umbilical notch
*Umbilical vessels
**Umbilical artery
**Umbilical vein
*Umbilical zone
*The Umbilical Brothers, two Australian comedic performers, David a ...
region. 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. The
outer lip is thin, showing the external
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 ...
within. The
columella
Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire.
His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the ...
is rather heavy, somewhat curved, backed up by the attenuated base and provided with a strong oblique fold at its insertion. The parietal wall is covered by a thin callus.
Distribution
This marine species is found off the coast of
Japan and the
Gulf of Thailand
The Gulf of Thailand, also known as the Gulf of Siam, is a shallow inlet in the southwestern South China Sea, bounded between the southwestern shores of the Indochinese Peninsula and the northern half of the Malay Peninsula. It is around in l ...
.
References
{{Taxonbar, from=Q6816922
Pyramidellidae
Gastropods described in 1906