A good symbol dictionary (like Liungman's*) will tell you that the first is Scorpio (although it seems that usually the arrow either curls to point up or goes diagonally down-right, not straight), closely associated with birth, sex and death; it's also the symbol for Separation in alchemy. The second one is Virgo; Distillation in alchemy. The third sign I couldn't find (I checked in Koch's "Book of Signs" too), but it seems to be closest to Saturn/lead, although it's also similar to the sign for Leo/Digestion. Or it could be a "facilitation" of Virgo.

* Interestingly, the first two signs are on the back cover of his book!

hhp

As I recall the Wingdings symbols were drawn by Chuck Bigelow. Zodiac symbols, apparently influenced by Chucks versions, also appear in Apple's Symbol font.

Cheers, Si