Of the crenulations about 20 appear upon the second and third, 22 upon the fourth, and 24 upon the penultimate turn.

They are marked by strong lamellar ribs, of which 12 occur upon the first, 14 upon the second, and 16 upon the penultimate turn.

There are 14 of these ribs upon the first, 18 upon the fifth, and 20 upon the penultimate turn.

Upon the penultimate turn they become decidedly irregular and enfeebled.

There are about 16 of these ribs on the first, 18 on the third, 20 upon the fourth, and 22 upon the penultimate turn.

Of these ribs, 14 occur upon the first, 16 upon the second, 18 upon the third, and 22 upon the penultimate turn.

They are marked by strong vertical axial ribs, of which 20 occur upon the second and third and 22 upon the penultimate turn.

Of the axial ribs, 14 appear upon the first, 16 upon the second, 20 upon the third, and 24 upon the penultimate turn.

There are 14 upon the first to ninth, 16 upon the tenth, and 18 upon the penultimate turn.

Of these ribs, 18 occur upon the second, 20 upon the third, 22 upon the fourth, and 27 upon the penultimate turn.