(Linné, 1758)
Description (shell):
Shell solid, with distinct periostracum; tall, conical, with up to ten almost flat-sided whorls; spire a little cyrtoconoid, slightly stepped at sutures. Sculpture of flexuous costae, strap-like spiral striae and fine growth lines. Costae numerous (20 or more on each whorl), more conspicuous on last whorl and part of penultimate whorl. Spiral striae less numerous (about thirteen on last whorl, five or six on whorls of spire), interacting with costae to produce raised, block-like reticulation, particularly conspicuous on spire. A deep spiral channel runs from base of siphonal canal to umbilical region of columella, below it a boss bearing four to six thin spiral striae. Aperture oval, with slight anal sinus and short, deep, markedly oblique siphonal canal. Outer lip arises tangential to last whorl, curving without inflection to tip of siphonal canal; thickened in mature shells, with internal teeth; often with labial varix. Inner lip spread widely over parietal region of last whorl; toothed or ridged in both columella and parietal regions in mature shells (N. reticulatus-drawing ).
Size:
Up to 30 x 14 mm.
Colour:
Cream or buff, often with darker subsutural bands; periostracum imparts a tan colour to live shells, though often discoloured by sulphides in sediments.
Animal:
Cephalic tentacles slender, each with a short, thickened basal portion bearing the eye. Siphon long (about half the shell length), held aloft in active animals. Foot long, with double-edged anterior and recurved anterio-lateral horns; posterior tip with slight fork and two metapodial tentacles. Operculum small, oval, with a frilled margin (N. reticulatus-animal).
Habitat:
Common near LWST, in sedimentary areas of rocky shores and sublittorally on soft substrata down to 15 m; often covered in sediment, with only siphon exposed.
Distribution:
Distributed from Canaries and Azores to Norway; common in the North Sea (Distr. N. reticulatus).