As Chrysodomus saturus:
Shell large, heavy, with about six whorls; whorls shouldered, more strongly on the earlier ones. Aperture more than half the length of the shell; canal short and slightly curved. Surface with very strong lines of growth, which bundle into obscure ridges. On the shoulder angle are seen obscure and irregular knobs, more strongly developed on the body whorl and the preceding one.
TYPE in Dr. Hunter Collection, British Museum. Type locality, King Georges Sound, Hudson Strait, Labrador.
RANGE. Arctic Ocean from Point Barrow to Bering Strait; Plover Bay, south and east to Cape Douglas, Alaska. Described as Buccinum saturum.

Shell small to medium for the genus (usually between 90 and 115 mm, occasionally up to 139 mm), thick, solid, usually heavy. Shape usually broad, oval, whorls convex or globose. Colour pale brown, reddish brown to purple brown. Sculpture variable, smooth or with broad, weak spiral cords, or with low axial folds, or a combination of both.

Neptunea ventricosa exhibits remarkable variation but has a characteristically heavy shell with a broad shape and rather inflated whorls. The species displays an impressive (even terrifying) degree of variability, which is exceptional even for Neptunea standards. Great variability occurs in shape (usually broad and inflated, but occasionally also slender with a high spire), thickness (usually thick, solid and heavy but occasionally also thin and rather fragile), sculpture (usually smooth, frequently with spiral cords or with axial lamellae, occasionally with a combination of both), surface dull (eventually eroded or encrusted) or brilliant (eventually polished by the environment), colour (commonly brownish with some reddish streaks, frequently purple tinged, rarely whitish). These features occur in all possible combinations and coexist. Several hundred specimens have been studied but "despite great efforts" no reason for any further splitting into species or subspecies has been found. Smooth shells and those with spiral sculpture are found together in the same egg-capsule, proving that they are merely a form.

* Neptunea ventricosa "northeast form".
Populations in the Beaufort Sea (Arctic Ocean) are found to be quite uniform; most specimens are smooth with a rather elongate spire. The size is smaller than average, usually 75-90 mm.

* Neptunea ventricosa "typical form".
Specimens from the northern and western Bering Sea may have a heavy, solid shell ornamented with a number of axial varices. The shape is rather oval, the whorls inflated, eventually with some traced of spiral cords. These shells are quite similar to the drawing in Martyn's book.

* Neptunea ventricosa "slender form".
Some specimens from the northern and western Bering Sea may have a heavy, solid, rather elongate shell, with a high spire, the upper whorls with some trace of spiral cords. These are the shells named behringiana by Middcndorff in 1849.

* Neptunea ventricosa "smooth form".
Some specimens from the northern and western Bering Sea may have a solid shell, nicely oval in shape without any pronounced spiral or axial sculpture. Usually some traces of spiral cords arc still visible, smooth shells arc rare. These arc the shells named conica by Aurivillius. Aurivillius referred to the specimens figured by Middcndorff in 1849 on plate 2, figs 3-4.

* Neptunea ventricosa "corded form". Some specimens from the northern and western Bering Sea may have a solid shell, oval in shape or with a high spire, with 1 or more pronounced spiral cords. Occasionally some traces of axial lamellae arc visible. These are the shells named cordata by Dall.

* Neptunea ventricosa "Okhotsk form".
Populations in the Sea of Okhotsk arc found to be uniform, most specimens being smooth with a rather broad shape. The shells are most similar to the typical form but differ in having a smaller adult size (usually 70-100 mm) and a slightly more curved outer lip. The Okhotsk form and the northern form are quite similar (smaller and smoother than the Bering Sea form) and are both situated at the extreme borders of the range.

Numbers of exceptional populations occur everywhere. For example, from an unknown place off southeastern Kamchatka Peninsula, where a population consisting of thin shells with wide aperture and large lamellae was found. Neptunea heros differs mainly in having a strong carina on the upper spire whorls and a slenderer shape.

Neptunea ventricosa is a high boreal to Arctic species, living in the northern Pacific, Sea of Okhotsk, Bering Sea and adjacent Polar Sea. It is known from south and east Sakhalin in the west and the northern Kuril Islands in the south, along the whole coast of the Bering Sea towards southern Alaska in the southeast. In the Polar Sea it is known from Cape Schelagski in the west (eastern part of East Siberian Sea) along the coast of the Chucki Sea and Beaufort Sea to the western part of the Northern Territories (Canada) in the cast. Bathymetric range shallow from subtidal down to 110 m deep. This species can survive temperature fluctuations down to -1.9° C (Golikov, 1963: 65). The southern boundary of the range is limited by the higher temperature, and most probably also the increasing salinity, of the Pacific Ocean. The southern boundary of the range off Sakhalin is extended by cold water from the East Sakhalin Current flowing southwards. The southern boundary of the range off the northern Kuril Islands is extended by cold water from the Okhotsk Current and East Kamchatka Peninsula Current flowing southwards. The northern boundary of the range roughly follows to the boundary of the polar ice-sheet and is limited by the influence of fresh water. Neptunea ventricosa can tolerate a certain desalinisation (caused by fresh water from melting ice) and temperature fluctuations, but its distribution is still limited when these influences become extremer, which is why it is found at the western coast of the outer Northern Territories (Banks, Prince Patrick, Borden and Ellcf Ringnes Islands) and not far inside the straits (Amundsen Gulf, McClure Strait and Prince Gustaf Adolf Sea).
Type locality: South-eastern Alaska, designated here. Gmelin (1791: 3498) recorded "Habitat ad sinum R. Georgii", a translation of Martins "K. George Sound, Rade de S. George". Later authors wrongly understood this locality as King George Sound, Hudson Strait, Labrador, in the northwestern Atlantic. An old map (1793-1794) by George Vancouver situated "the empire of King George III" at the Chicagoff and Baranoff archipelago. The type was collected in the summer of 1778 during the third and last voyage of Captain James Cook, as was Buccinum liratum (Neptunea lyrata), but whether it originates from this archipelago, or from Unalaska Island (Eastern Aleutians), or from elsewhere is still uncertain.