Belemnite
BELEM'NITE, noun [Gr.a dart, or arrow, from the root of pello, to throw.]
Arrow-head, or finger stone; vulgarly called thunder-bolt, or thunder stone. A genus of fossil shells, common in chalk and limestone. These shells consist of an interior cone, divided into partitions connected by a syphon, as in the nautilus, and surrounded by a number of concentric layers, made up of fibers radiating from the axis. These layers are somewhat transparent, and when burnt, rubbed or scraped, give the odor of rasped horn. The species are now extinct.