''Pyramidella adamsi'', common name the Adams' pyram, 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 Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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.Rosenberg, G. (2011). ''Pyramidella adamsi'' Carpenter, 1864. Accessed through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific speciali ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=575934 on 2012-01-12Keen M. (1971). Sea shells of Tropical West America. Marine mollusks from Baja California to Perú. (2nd edit.). Stanford University Press pp. 1064 This species was named for

Charles Baker Adams Charles Baker Adams (January 11, 1814 – January 19, 1853) was an American educator and naturalist. Biography He was born in Dorchester, Massachusetts in 1814, the son of Charles J. Adams and Hannah Baker. He graduated from Phillips Academy in ...

(1814-1853), an American naturalist.

Description

The slender shell has an elongate-conic shape. The early whorls are white, later ones diversely variegated, frequently dark brown, yellowish-brown or purplish-brown on the later turns. It is this striking variegated color pattern which at once distinguishes this species from the other West American forms. The length of the shell varies between 11 mm and 19 mm. The spaces between the sutures are crossed by light areas, which are vertical in the middle, bending suddenly forward at the periphery and the summit, thus forming )-shaped areas. The space immediately below the peripheral sulcus on the base has short light areas, corresponding to those above the sulcus, but with retractive slant. The space between these light areas, near the summit, forms a series of elongated dark spots. The

varices A varix (pl. varices) is an abnormally dilated 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 usua ...

which are disposed at irregular intervals are chestnut brown, preceded usually by a band of white. The posterior half of the base is light chestnut brown; the anterior white. The

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 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, two, forming a planorboid

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 ...

whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-half immersed. The twelve 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 flattened. They are moderately shouldered at the summit, which is crenulated. The periphery at the body whorl contains a strong sulcus. The base of the shell is moderately long, and well rounded. The entire surface of the spire and the base is marked by fine lines of growth and exceedingly fine, microscopic spiral striations. 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 convex outer lip is thin, showing the following color markings within: a white zone at the periphery, a narrow chestnut band immediately posterior to the periphery and another at the summit, a broad band extending over half the base immediately below the peripheral zone. Deep within, the lip is reinforced by five strong, spiral cords, one at the periphery, two on the base, and two between the periphery and the summit. 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 ...

is short. The thin

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 strong, and provided with a strong fasciole. The posterior fold is very strong, and lamellar: the anterior two are very oblique, and slender.Dall & Bartsch, A Monograph of West American Pyramidellid Mollusks, United States National Museum Bulletin 68, p. 21-22: 1909
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Distribution

This species occurs in the Pacific Ocean on sand and mud along the low-tide zone off

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States ...

and 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 ...

References

External links

To World Register of Marine Species
{{Taxonbar, from=Q3171145 Pyramidellidae Gastropods described in 1864