''Calliclava alcmene'' 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 ...

Drilliidae The Drilliidae are a taxonomic family of small predatory sea snails with high-spired shells. They are classified as marine gastropod mollusks in the superfamily Conoidea. This family has no subfamilies. It consists of about 30 genera and approxi ...

Description

The size of an adult shell varies between 13.5 mm and 19 mm. (Original description) The small shell is pinkish white and polished. It is acute, with a flat-topped

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 ...

of two polished, prominently peripherally keeled

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 and about eight subsequent whorls. The suture is appressed, with a retractively nodulous, thickened band in front of it, forming the posterior margin of the anal fasciole. The

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 (on the body whorl 22) somewhat sigmoid rounded ribs with subequal interspaces, reaching from the suture over the whorl to the

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 ...

. They are constricted over the narrow anal fasciole and feebler on the anterior part of the body whorl. These ribs are cut into subnodulous segments by deep narrow sharp spiral grooves, with much wider interspaces, two or three on the

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 ...

, nine or ten between the fasciole and the siphonal canal on the body whorl. On the canal are five or six coarse close-set threads. 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 ...

of the holotype (probably not quite mature) is rather narrow. The anal sulcus is narrow, not deep. The outer

lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

is thin, sharp, prominently arcuate. The inner lip is erased. 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 short and twisted. The short siphonal canal is hardly differentiated.Dall (1919) Descriptions of new species of Mollusca from the North Pacific Ocean; Proceedings of the U.S. National Museum, vol. 56 (1920)
(described as ''Clathrodrillia (Kylix) alcmene'')

Distribution

This species occurs in the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...

, Western Mexico.

References

External links

* {{DEFAULTSORT:Calliclava Alcmene

alcmene In Greek mythology, Alcmene () or Alcmena (; Ancient Greek: Ἀλκμήνη or Doric Greek: Ἀλκμάνα, Latin: Alcumena means "strong in wrath") was the wife of Amphitryon by whom she bore two children, Iphicles and Laonome. She is best k ...

Gastropods described in 1919