Sinistral: extending to or at the left from the median line.

If we were very fortunate, we might find a sinistral, or “left-handed” specimen.

Sinistral: Having the aperture of the shell at the left; opposite of dextral.

This is carried outward in a sinistral spiral to the noded shoulder.

Gasteropod shells may be sinistral or dextral, according as the whorls turn to the left or right.

The sinistral circuit is one in which the center is on the left hand, while the dextral circuit has its center to the right.

With unimportant differences, the process of metamorphosis in the sinistral fish is parallel to that in the dextral fish.

A genus of minute land shells, resembling Vertigo, but separated because they are dextral, while Vertigo is sinistral.

Dextral animals, with shell coiled pseudo-sinistrally; operculum with sinistral spiral; pallial cavity dorsal.

Shell bulimoid, dextral or sinistral; radular teeth, expanded at their extremities and multicuspidate.