''Pilsbryspira bacchia'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Pseudomelatomidae Pseudomelatomidae is a family (biology), family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda (Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), Bouchet & Ro ...

, the turrids and allies.

Description

The shell grows to a length of 15 mm, its diameter 5.5 mm. (Original description) The solid, biconic, acute shell is slate gray with whitish projections. 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 called " ...

(eroded) consists of two brownish

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). In nature File:Photograph and axial plane floral diagra ...

s, apparently smooth. It is followed by nine subsequent whorls. The suture is distinct, appressed, bordered by a small thread behind and a strong white cord in front betAveen it and the fascicle which is constricted narrow and minutely spirally striated. The other spiral sculpture consists of (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. Spire ...

two) peripheral whitish cords, the anterior stronger and swollen where it passes over the ribs. On the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk ...

in front of the periphery are seven similar but smaller cords with wider, minutely striated interspaces sometimes carrying an intercalary thread. On 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 i ...

are about half a dozen close-set threads. The axial sculpture consists of (on the body whorl 10) short rounded ribs prominent only on the periphery and extending from the fasciole to the siphonal canal, with subequal interspaces. There is also a prominent rounded

varix A varix (: varices) is an abnormally dilated blood vessel with a tortuous course. Varices usually occur in the venous system, but may also occur in arterial or lymphatic vessels. Examples of varices include: * Varicose veins, large tortuous veins ...

behind the outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

. The outer lip is sharp-edged, smooth internally. The

anal sulcus The anal sulcus, also called the anal sinus or anal canal, in Gastropods is a notch, a shelly tube at the top of the Aperture (mollusc), aperture. It is the first notch close to the Suture (anatomy), suture. It houses the anal siphon through which t ...

is conspicuous, rounded, short, with a strong subsutural callus. The inner lip is erased, dark purple as well as the throat. The

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

is straight and short. The siphonal canal is hardly differentiated from the

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

. Dall (1919) Descriptions of new species of Mollusca from the North Pacific Ocean; Proceedings of the U.S. National Museum, vol. 56 (1920)

Distribution

This species occurs in the

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

, Mexico.

References

External links

*
Gastropods.com: ''Pilsbryspira bacchia''
{{DEFAULTSORT:Pilsbryspira Bacchia bacchia Gastropods described in 1919