Cucullus biliosus Röding, 1798: 39, no. 489 (representation of lectotype, Chemnitz 1788: pl. 139, fig. 1294 (42 x 25 mm); "Gulf of Mannar, between India and Ceylon ").

Conus punctatus Hwass in Bruguière, 1792: 628, no. 23 (lectotype, MHNG (54 x 33 mm) (Walls 1979); "Océan Africain").

Conus parvulus Link, 1807: 106 (representation of lectotype, Martini 1773: pl. 63, fig. 707 (20 x 12 mm); locality unknown).

Conus roseus Lamarck, 1810: 37, no. 32 (lectotype, same as that of C. biliosus; "Antilles").

Conus piperatus Dillwyn, 1817: 401, no. 86.

Conus concinnus Sowerby II, 1866: 329, no. 438, pl. 28, fig. 646.

Conus sapphirostoma Weinkauff, 1874: 268.

Virroconus imperator Woolacott, 1956: 72, fig. 3 (holotype, AMS (42 x 23.5 mm) (Röckel et al. 1995); "Trinity Bay, Queensland, Australia ").

Conus biliosus meyeri Walls, 1979: 3 (holotype, DMNH (44 x 24.5 mm) (Walls 1979); " South Africa, Natal, Genezzano".

Conus neoroseus da Motta, 1992: 29–30 ("Tabayas Bay, Luzon, Philippines ").

Material examined: MBMCS 114, 28 specimens, SL 36–52 mm; SW 15–24 mm.

Description. Shell moderately small to large, solid, with a low gloss or dull finish; outline conical, sides straight or inflated posteriorly. Body whorl usually elongate, covered with numerous low and undulating spiral ridges from base to shoulder, ridges weaker near mid-body, below shoulder and heaviest near base; numerous axial and spiral growth threads, lines, and flaws often present, sometimes smooth. Shoulder wide, roundly angled, weakly coronated or undulate, usually slightly concave above. Spire low, bluntly pointed, sides straight to slightly concave, spire whorls distinctly coronate. Aperture moderately wide, uniform; outer lip nearly straight, moderately thick and sharp.

Distribution. Conus biliosus was reported to occur from Bombay (Subrahmanyam et al. 1952) to Okha in Gujarat (as ‘ C. punctatus Chemnitz’) on the west coast (Menon et al. 1961). In the east coast, it has been found as far north as Vizhagapattinam (Mitchell 1867) to Madras (Melvill & Standen 1898; Röckel et al. 1995), Rameswaram (as ‘ C. piperatus Dillwyn’) and Gulf of Mannar in the South (Thurston 1890, 1895; Satyamurti 1952; Röckel et al. 1995).

The specimens described herein were collected from Keelakarai by diving in 15–20 m mainly on sand bottom and at Yerwadi by trawling in 10–35 m (Table 6).

Remarks. The restricted distribution of C. biliosus only to two stations (S-18 & S-19) is yet to be studied.