With a glorious textile-like tent pattern the « Bengal Cone » is an exceedingly famous conid ranging from Andaman Sea to Bay of Bengal, reaching southeastern India. Once exceedingly rare and most sought-after, today it has become much easier to obtain and is considered only uncomm.on. Large, perfect specimens are however still rarely seen and much treasured. A carnivorous and predatory gastropod feeding on polychaete worms, it inhabits sandy to muddy bottoms of moderate depths around -50-150m deep. Typical shell length around 100mm., extremely large specimens may exceed 140mm. Although it resembles the closely related congener « Glory-of-the-Sea » Cylindrus gloriamaris (Chemnitz, 1777) and was thought to be a local form of it when initially discovered, it can be distinguished relatively easily by its taller spire, narrower shoulder, and larger tent-like patterns. From this similarity, it is also known as the « Glory-of-Bengal ». One of the most beautious species described by the eminent Japanese malacologist Prof. Takashi Okutani, it remains one of his favourite species of all time.

Conus bengalensis Okutani, 1968 is currently considered a monotypic species whose known range classically extends from the Andaman Sea westward across the northern Indian ocean to and including southern India. Of the Indo-Pacific "Glory Cones," this is the only member with a continuous known distribution that includes two oceans. However, upon closer examination, the species assorts into three recognizable populations of which one has recently been described as a highly endemic, distinct species:

Population 1: Herein regarded as the nominate population, has a distribution from the eastern Indian Ocean, notably the Andaman Sea, westward to the eastern coast of southern India. These moderate to moderately large shells are narrowly conoid-cylindrical to narrowly conical with an almost straight to centrally slightly concave last whorl (Rockel et al.., 1995). The relative spire height is moderate, averaging from 0.16 -0.24 (Rockel et al.., 1995). Based on personal measurements of 11 specimens, the relative spire height was found to average 0.23 (range 0.19 - 0.31) and the relative diameter to average 0.31 (range 0.30 - 0.32). Shells have a white ground color with fine light to dark brown reticulated lines and yellowish brown flecks and blotches arranged in three spiral rows with blackish-brown textile lines and overlaid by a profusion of small to moderate white tents (Rockel et al.., 1995; Kersten, 2015-Figs 2 A, B).

Population 2: Predominantly occurs in southern and western India including some range overlap with the
nominate form. Compared with that form, these shells have a broader, more convex outer whorl, particularly a wider shoulder. Based on measurements of 8 specimens, the average relative spire height is 0.24 (range 0.21 - 0.30) and relative diameter is 0.33 (range 0.34 - 0.38). In addition, the spiral bands are reportedly broader and more orangey than in the nominate form (Rockel et al.., 1995; and Monnier et al.., 2018) although this distinction was not found to be consistent.

Population 3: In recent years, a large number of specimens have been found in eastern Indonesia, exclusively within Taluk Saleh (Saleh Bay) bordering on the Flores Sea (extreme western edge of the tropical south Pacific. To date, these are the only members of the C. bengalensis clade not from the greater Indian Ocean basin. Currently, they are exclusively known from within the bay, having no range overlap whatsoever with its sisters. By comparison, these specimens average notably smaller with a distinct pattern of larger, more open tents and often reduced spiral bands that are less orangey in color , somewhat resembling the patterning of nominate C. milneedwardsi. Based on measurements of 28 specimens, the relative spire height averages about 0.26 (range 0.21 - 0.32), making it proportionally taller-spired than the other forms of C. bengalensis, at times overlapping the extremely tall spire of C. milneedwardsi. This attribute appears to be unrepeated in nominate or Indian specimens of C. bengalensis. The relative diameter is 0.37 (range 0.32 - 0.41). Recently, this population was recognized as a distinct subspecies: Cylinder bengalensis sumbawaensis Verbinnen, 2022 (Verbinnen, 2022) and very shortly thereafter, as a distinct species: C. sumbawaensis Verbinnen, 2022 (Veldsman et al.., 2022). Perhaps the most compelling argument for this distinction is that while relatively common, it has an isolated and entirely endemic range within just Teluk Saleh on Sumbawa Island. No other member of the broad "Glory Cone" group is so uniquely isolated in its range, particularly in light of its apparent substantial abundance.

Within each of these populations, there is distinct, albeit at times, subtle intra-populational consistency; at least to the extent that members are recognizable based on visual inspection alone without knowledge of their location of origin. Additionally, the Andaman Sea and Indian populations have minimal range overlap, at least insofar as currently known specimens are concerned, although that may be an artifact of localized collecting practices. That is not likely the case with C. sumbawaensis. Additionally, while the Andaman and Indian forms of C. bengalensis are almost exclusively found in very deep water (ca. 50-150 m), C. sumbawaensis specimens are being collected in relatively shallow water (ca. 10-20 m). Of additional note, Taluk Saleh, Indonesia is currently the only place where C. gloriamaris co-occurs with any other form, in this case, C. sumbawaensis.

Found at: Racha Island, Phuket, Thailand