Conus
(Hemiconus) trisulcatus (Tracey & Craig, 2017)
Diagnosis of H. trisulcatus n.
sp. : Narrowly fusiform Hemiconus with tall
spire; whorls weakly angular to flat sided with 3 punctate grooves below the
suture and fine spiral threads covering the remainder of the shell.
Description of H. trisulcatus n.
sp. : Small narrowly turriform-fusiform shell ;
spire 37-46% of shell height ; Height : width ratio 3 - 3.5:1 ; protoconch large,
diameter c. 730 μm., paucispiral of 1.75
whorls ; Early whorls flat sided with flush sutures, typically ornamented with
7-8 low, rib-like nodules per whorl which may be obscure or even absent ; later
whorls tending to develop a blunt angularity in mid-whorl that becomes a
rounded shoulder on the last whorl ; subsutural collar beaded, often only
weakly, and underscored by 3 regularly spaced spiral grooves which are made
punctate by the raised growth lines within them ; body whorl straight-sided and
covered in numerous close, fine spiral threads becoming more prominent towards
the base, crossed by almost vertical growth striae ; sinus wide and very
shallow, outer lip gently curved ; aperture very narrow with parallel sides ;
columella straight, callus hidden from view. Most angular form 20.5 x 6.9 mm.,
narrowest 14.6 x 4.1 mm.
Discussion of H. trisulcatus n. sp. : The more acute,
flat-sided early whorls, triple grooved ornament, very close, fine spiral
striae and tendency to develop an angular whorl profile in some individuals separates
this from other slender Hemiconus such as H. cryptoconoides Cossmann
& Pissarro, 1901.
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Figs. 19-22 : Hemiconus trisulcatus (Tracey & Craig, n. sp) 19. Paratype NHMUK PI TG 26855 (leg. B. CRAIG) Hautteville 20a-b. Paratype NHMUK PI TG 26856 (leg. S. TRACEY) Hautteville 21. Paratype NHMUK PI TG 26857 (leg. B. CRAIG) Néhou 22a-c.
Holotype (22c. protoconch) NHMUK PI TG 26858 (leg. S. TRACEY) Hautteville |
Bibliografia Consultata