''Pyrgocythara hemphilli'' is a species of
sea snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...
, a marine
gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusk in the
family Mangeliidae.
Description
The length of the shell attains .
The small, glistening, acute shell is brownish, with the projecting sculpture paler. 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 ...
is dark brown, glassy, and rather irregularly coiled. It contains one smooth
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 floral ...
followed by a peripherally keeled turn and about eight subsequent whorls. The suture is distinct, appressed, with a nodulose band in front of it where the ends of the ribs are cut off by a very narrow fasciolar constriction. The spiral
sculpture consists of a few incised lines cutting only the interspaces between the ribs, on the
spire. On the
body whorl
The body whorl is part of the morphology of the 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 gastropods
In gastropods, the b ...
there are six or seven of these lines, with much wider interspaces, followed by three strong cords close-set 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 is ...
. The axial sculpture consists of (on the body whorl about 13) protractively oblique whitish narrow ribs extending from the fasciole to the cords of the siphonal canal, with subequal interspaces and not continuous up the spire. The silky incremental lines are evident. The
aperture is narrow. 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
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and fo ...
is deep and rounded, with a strong subsutural callus. The outer
lip is sharp-edged, with a feeble
varix
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 ...
and a brown spot behind it. The inner lip and the
columella show a thick coat of white enamel, the throat not lirate. The siphonal canal is constricted, very short, deep, and slightly recurved.
Distribution
''P. hemphilli'' can be found in Caribbean waters, ranging from the western coast of
Florida to the
Bahamas.
[Tunnell, John W., Jr., Felder, Darryl L., & Earle, Sylvia A., eds. ''Gulf of Mexico Origin, Waters, and Biota, Volume 1: Biodiversity.'' Texas A&M University Press, 2009. 667.]
References
Bartsch, Paul, and Harald A. Rehder. "New turritid mollusks from Florida." Proceedings of the United States National Museum (1939).Rosenberg, G., F. Moretzsohn, and E. F. García. 2009. ''Gastropoda (Mollusca) of the Gulf of Mexico'', pp. 579–699 in Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, College Station, Texas
External links
*
Gastropods.com: ''Pyrgocythara hemphilli''
{{DEFAULTSORT:Pyrgocythara Hemphilli
hemphilli
Gastropods described in 1939