Crassispira maura
Crassispira maura, common name the dark-coloured pleurotoma, is a species of sea snail, a marine gastropod mollusk in the family Pseudomelatomidae. Pleurotoma maura Kiener L.C., 1840 is a synonym of Pilsbryspira aterrima (Sowerby, G.B. I, 1834)

Description
The length of the shell varies between 45 mm and 85 mm. The turreted shell is acuminated and blackish brown. The whorls are tuberculated in the middle, dotted round the lower part, whilst the upper part exhibits a depression from the rilling up of the sinus. The siphonal canal  is recurved. Distribution
This marine species occurs from Mazatlan, Mexico to Ecuador

References

 G.B. Sowberby I. Proc. Geol. Soc., 1833, p. 137
 Reeve, Conch. Syst., vol. ii. pi. 133. f. 4. External links
 
 

maura
Gastropods described in 1834