sinistrorsaladj.

1823 W. Henry Elements Exper. Chem. (ed. 9) I. v. 197 It was easy, by passing the wire round the rod, in one direction or the other, to form a dextrorsal helix, proceeding from the right hand towards the left, as in the tendrils of many plants; or a sinistrorsal, or left helix, proceeding downwards from the left hand to the right above the axis.

1882 Med. News 30 Sept. 371/2 It must be remembered that the north pole of the magnet must be downwards if the helix is dextrorsal, or the reverse, if it is a sinistrorsal helix.

1926 Amer. Jrnl. Bot. 13 64 It can be determined that in some cases the helix [of a chromosome] is dextrorsal and in other cases sinistrorsal.

1941 U.S. Patent 2,234,247 1/1 One wire of each pair will be of dextrorsal twist, while the other wire of each pair is of sinistrorsal twist.

1830 Zool. Jrnl. 5 270 It agrees with Physa more particularly in being a sinistrorsal shell.

1840 E. Blyth et al. Cuvier's Animal Kingdom 345 The whorls turn obliquely to the right side in nearly all the species, but in a small number to the left; and the latter are named reversed, (or sinistrorsal).

1868 Nat. Encycl. I. 697 Ancylus, a genus of little fresh-water snails..; the animal being, as Rang considers, sinistrorsal.

1967 Palaeogeogr., Palaeoclimatol., Palaeoecol. 3 311 Only the shells of the latter [sc. the genus Thais] were inhabited by hermit crabs, as the Neptunea is sinistrorsal.

1884 J. G. Jeffreys in Proc. Zool. Soc. 364 The heterostrophe or sinistrorsally spiral apex.

1922 Official Gaz. (U.S. Patent Office) 14 Feb. 375/1 A pump comprising a casing having a suction and a delivery chamber, an impeller rotatably mounted therein,..and a sinistrorsally disposed passage in the suction chamber adjacent said impeller.

1981 O. N. Allen & E. K. Allen Leguminosae 171 Erect or scandent shrubs with long, sinistrorsally twining branches.