Range: S. and N. W. Madagascar.
Description: Medium-sized, moderately solid. Last whorl ventricosely conical to conical; outline convex at right side, sigmoid to nearly straight at left side. Shoulder angulate and strongly tuberculate; tubercles widely spaced and outward- pointing. Spire of moderate height, outline concave. Larval shell of about 2 whorls, maximum diameter about 1 mm. Postnuclear spire whorls tuberculate. Teleoconch sutural ramps concave, with 1 increasing to 4-5 spiral grooves; grooves with a spiral thread on last ramp. Last whorl with granulose spiral ribs from base to subshoulder area, followed by weaker ribs; a spiral thread often present anterior to the ribs.
Ground colour white. Last whorl with spirally aligned brown bars and flecks, the latter concentrated in a spiral band on each side of centre. Base and basal part of columella pinkish violet. Larval shell white. Postnuclear sutural ramps with brown radial streaks. Aperture tinged with pinkish violet.
Habitat and Habits: Holotype in 75-90 m, paratype in about 600 m.
Discussion: C. helgae is similar in size and pattern to C. acutangulus and to C. sulcatus form samiae. C. acutangulus differs in its less strongly tuberculate to smooth shoulder, broader last whorl (RD 0.65-0.75) with a more regular sculpture, in its higher spire (RSH 0.22-0.37), and its highly multispiral larval shell (3.5-4 whorls). C. sulcatus form samiae is larger (50-65 mm) and has at least 3 larval whorls; its last whorl is generally broader (RD 0.62-0.67), the granulose ribs on last whorl are stronger and its last whorl pattern forms brown spiral bands. A specimen similar to the holotype is present in the MNHN. Further shells of this species have recently been collected in S. Madagascar.
C. helgae range map
This section contains verbatim reproductions of the accounts of 316 species of Conus from the Indo-Pacific region, from Manual of the Living Conidae, by Röckel, Korn and Kohn (1995). They are reproduced with the kind permission of the present publisher, Conchbooks.
All plates and figures referred to in the text are also in Röckel, Korn & Kohn, 1995. Manual of the Living Conidae Vol. 1: Indo-Pacific Region.
The range maps have been modified so that each species account has it own map, rather than one map that showed the ranges of several species in the original work. This was necessary because each species account is on a separate page on the website and not confined to the order of accounts in the book.