Middle Ordovician – Silurian
Bucania is an extinct genus of epifaunal detritivores
Identification in Hand Sample:
- Shell has transverse ornamentation
- Aperture may be somewhat expanded
- Ornament spiral threads normal to anterior margin
- Generally a wide umbilicus
- Surface markings consist of equal or unequal revolving riblets and growth lines
- Shell has transverse ornamentation.
Treatise on Invertebrate Paleontology, Part I, Mollusca 1 (1960):
- Aperture but little, if at all, expanded, wider than long, especially at rear; ornament spiral threads normal to anterior margin and converging forward or both types of threads crossing to form a pitted surface.
Ulrich & Scofield (1897):
- Shell consisting of three to five more or less depressed volutions coiled in one plane, with generally a wide umbilicus and not greatly – never abruptly – expanded aperture. Surface markings consisting of equal or unequal revolving riblets and lines of growth, together producing a more or less cancellated appearance. Revolving lines wavy or wrinkled, oblique, especially in the umbilicus, crossing from the ventral side of a whorl to the dorsal slit-hand in the space of about one-half a volution. Frequently they are interrupted by strong lamellae, the wavy edges of which are parallel with the lines of growth and the apertural margin. Aperture transverse and somewhat reniform in the typical section, higher and relatively larger in the B. nashvillensis section. In the former the lips are thin, the outer one sinuate, and the sinus prolonged into a rather long narrow median slit; in the latter the inner lip is rather thick and the slit shorter. Slit-band distinct, raised or depressed.