Clavatula helena is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

, a marine gastropod mollusk in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Clavatulidae

Clavatulidae

Clavatulidae is a taxonomic family of sea snails, marine gastropod mollusks in the superfamily Conoidea.The family is not well differentiated morphologically....

.

Description

The size of an adult shell varies between 30 mm and 40 mm. The fusiform shell is moderately long. The ground color of the shell is yellow, superimposed with blotches and streaks of chestnut brown. The space between the sutures is brown in the anterior half. The teleoconch is flattened with a narrow keel posterior to the broad, anal sinus. The anterior half of the teleoconch has between 8 and 12 feeble axial ribs. All over the spire

Spire (mollusc)

A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...

 are very fine growth lines. The periphery of the body whorl

Body whorl

Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...

 is well rounded. The aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is elongately oval. The thick outer lip

Lip (gastropod)

In the shell of a gastropod mollusk , the margin of the aperture is called the lip or the peristome. In other words, this is a term used to describe part of gastropod shell anatomy....

 is notched at the anal sinus. The parietal wall shows a very thick callus. The siphonal canal

Siphonal canal

Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is drawn into the mantle cavity and over the gill and which serves as a chemoreceptor to locate food. In many carnivorous snails, where the siphon is particularly long, the structure...

is very short.