''Knefastia princeps'' is a

species In biology, a species is the basic unit of 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 the appropriate s ...

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 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 e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Pseudomelatomidae Pseudomelatomidae is a family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda ( Bouchet & Rocroi, 2005). In 1995 Kantor elevated the subfamily Pseudomelatomina ...

, the turrids and allies. This magnificent species, one of the finest in a generally striking genus, appears nearest to K. dalli Bartsch among described forms, differing in its larger size, more slender form, the relatively longer and attenuate canal, the slender and well-spaced spiral cords, the very much fewer and less nodulous axial ribs, the more open sinus, and the warmer and brighter coloring, especially of the interior. The single example taken was dredged up alive.

Description

fusiform Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from one or both ends, such as an aneurysm on a b ...

shell that is moderately large and elongated. larval shell decollated in

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

but persisting whorls 81/^, turreted, strongly convex, sloping above to a high, subangulate shoulder; a flattened fold-like ridge strongly appressed against the suture is subtended by a shallow spiral furrow in the rather wide anal fasciole, the latter sculptured otherwise mainly by the very strong and coarse incremental striae and a few weak traces of low spirals; body of whorl marked by from 7 to 8 massive axial ribs (there are 7 on the last whorl) which are slightly knobbed on the shoulder, and 4 low but strong spiral ridges which over-ride both the axial ribs and their interspaces, the two central ridges being a trifle more widely separated than either is from its outer neighbor; base with about 13 or 14 gradually weakening spirals; the axial ribs pass onto the base but become obsolescent in the region of the canal. Aperture unarmored, about 45% the length of the shell, elongate-pyriform, acute posteriorly; outer lip sharp-edged, hardly crenulated by the spiral ridges, its margin convex in front of the strong open anal notch which nearly subtends the end of the suture. The canal is open and fairly long. The columellar wall is somewhat erose parietally, covered with a moderate wash of shining enamel.

Periostracum The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and ...

is shining, the spire and main portion of body-whorl lustrous Antique Brown, paling anteriorly and on the nodes to Raw Umber, the spiral ridges sharply paler and the anterior portion of the shell as well, even to Chamois at the extreme portion and on the spirals, with one or two darker bands under the periphery. The interior is polished and bright, near Cinnamon to a Pinkish Cinnamon. Operculum is a little smaller than the aperture, it is acute in front and more blunt posteriorly, with a shallow furrow that is running parallel to the inner margin. The length of the holotype is 60.3 mm, its diameter 19.9 mm.

Distribution

This marine species occurs from

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

, Mexico, to

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, in pebble, mud and shell bottoms.

References

Berry, Samuel Stillman. "Notices of new west American marine Mollusca." San Diego Society of Natural History, vol. 11, 1953

External links

*
Gastropods.com: ''Knefastia princeps''
princeps Gastropods described in 1953 {{Pseudomelatomidae-stub