Shell delicate,thin,inflated, six-whorled,with a delicate greenish gray, slightly fringed, dehiscent epidermis; spiral sculpture of numerous sub-equal flatfish threads, with narrower rounded interspaces and no intercalary threads; these threads are, as usual, slightly coarser ou the base and liner behind the shoulder of the whorl near the suture; at the shoulder a single more prominent but not much larger thread slightly turriculates the spire; whorls full and rounded, especially on the base; suture distinct but not channeled ; aperture wide, outer lip somewhat patulous in front, receding toward the suture; canal wide, short, hardly discriminated from the aperture, very slightly recurved; fasciole distinct but not prominent; pillar thin, twisted; inner lip smooth, white, slightly excavated, or the limy outer layer of the shell is there absorbed and I he space covered with a thin wash of polished glaze; except for the epidermis the shell is pure white. The outer lip is very thin and but slightly reflected. The nucleus is eroded on the surface so that its character is not determinable. Maximum longitude of shell, 46 MM of aperture, 24; maximum latitude of shell, 29 MM.

The operculum is oval, slightly pointed towards the extremities, thin and normal, the nucleus being near the margin about three-eighths of the distance from one end toward the other. The soft parts are whitish, the tentacles moderate, the swelling for the eye present, but usually unpigmented, though a trace of the color seems to remain iu some specimens. The gills and osphradium are as usual. The verge is as long as the foot, stout, geniculate, razorblade shaped, the thin edge being to the right or when recurved and turned under, as is generally the case, to the left; the distal end is squarish, rounded at the corners, the thicker angle terminating with a small acornshaped papilla. The dentition recalls that of B. undatum, but the central tooth has five sharp, spikeshaped, subequal denticles, the two inner cusps of the laterals, while smaller than the outer cusp, are more nearly its size, the middle one of the three tends to be smaller and to have one or even two minute denticles, one on each side in the latter case, near its base. None of the specimens were fully mature, though the one figured had formed the beginning of the reflected lip, so that its shape could be ascertained ; but it is probable that fully mature specimens would have the reflection wider and stronger.

The « Turban Whelk » is a deep-water buccinid native to the northern Pacific, best known from the West coast of North America. Although generally an inhabitant of sandy to muddy bottoms of deep water around -700~2500m, it is also an important member of chemosynthetic ecosystems California and Oregon, USA, being comm.only found in hydrothermal vents (e.g., Explorer Ridge), methane seeps, and on whale falls. It is a carnivorous gastropod but also scavenges when the opportunity arises. There are two forms, one with an obvious spiral cord on the shoulder and the other with a rounded shoulder. Though supposedly a comm.on species, it is quite an uncomm.on species in the shell trade. It is the type species of subgenus Viridibuccinum. Typical shell length around 40mm., very large specimens may exceed 60mm. A similar species, Buccinum thermophilum Harasewych & Kantor, 2002 is known from the Endeavour Vent Field, Juan de Fuca Ridge, and differs from B. viridum by smaller, narrower, more higher spired shell and a much more ovate aperture. Furthermore, the spiral ridges in B. thermophilum is generally much sparser.

Shell delicate, thin, inflated, six-whorled, with a delicate greenish gray, slightly fringed, dehiscent epidermis; spiral sculpture of numerous sub-equal flattish threads, with narrower rounded interspaces and no intercalary threads; these threads are, as usual, slightly coarser on the base and finer behind the shoulder of the whorl near the suture; at the shoulder a single more prominent but not much larger thread slightly turriculates the spire; whorls full and rounded, especially on the base; suture distinct but not channeled; aperture wide, outer lip somewhat patulous in front, receding toward the suture; canal wide, short, hardly discriminated from the aperture, very slightly recurved; fasciole distinct but not prominent; pillar thin, twisted; inner lip smooth, white, slightly excavated, or the limy outer layer of the shell is there absorbed and the space covered with a thin wash of polished glaze; except for the epidermis the shell is pure white. The outer layer is very thin and but slightly reflected. The nucleus is eroded on the surface so that its character is not determinable. Max. long, of shell, 46; of aperture, 24; max. lat., 29 mm. (Dall.)
TYPE in United States National Museum. Type locality, Station 2839, off Santa Barbara Islands, California.
RANGE. Santa Barbara Islands, California, in 414 fathoms.

USA, off Santa Barbara Islands, California, in 414 fathoms, sand.