314 
Proceedings of the Royal Society 
(1 and 2) above: with two additional we have the following, — 
figured in my first paper. 
With three we have two apparently different forms, 
These are, however, only transformations of the six-crossing amphi- 
cheiral form (figs. 3 and 4 of my last paper), and are directly trans- 
formable into one another. They are, of course, unchanged if the 
lower part be reversed, for the upper parts are symmetrical. 
But when we add four new crossings, as below, instead of the 
single crossing removed, we get the two equivalent figures 
which are not transformable into one another by the processes of 
my first paper. In fact the schemes will be found to be incom- 
patible, begin each where we choose. In Listing’s notation their 
type-symbols would stand respectively, thus — 
2h -f- 2r 3 'j C r 5 _j_ ^4 _j_ r 3 _|_ 
2? + 3 P j and (2^ + 3^ 
The schemes are 
AEBFCBDABGBCGD I A and ADBFGABGBBBFGC | A. 
j 
But even this simplest amphicheiral form has other applications. 
