In contrast, the circulation of air in the vicinity of a low pressure area is counterclockwise with the force tending to be directed inward toward the center.
"A Quantitative Study of the Nocturnal Migration of Birds. Vol.3 No.2"
George H. Lowery.
I saw a cloud of screwfish pass over and around us, spinning rapidly as they swam as though on lengthwise axis-they always spin counterclockwise, never clockwise.
"Four-Day Planet"
Henry Beam Piper
In general, it is a great aid to the eye if this is carried out with some system, and the following suggestions are given as in accord with the best authors who have given any attention to the subject: 1. In general, letter a figure counterclockwise, for the reason that we read angles in this way in higher mathematics, and it is as easy to form this habit now as to form one that may have to be changed.
"The Teaching of Geometry"
David Eugene Smith