Mullets are those Meteors which the ignorant call Falling-Stars.

From The Grammar of Heraldry by Samuel Kent, p50


[In addition to the label for the eldest son,] the other marks of difference are: For the second son a crescent; for the third son a mullet; for the fourth son a martlet; for the fifth son an annulet; for the sixth son a fleur-de-lis; for the seventh son a rose; for the eighth son a cross moline; for the ninth son a double quatrefoil.

A Complete Guide to Heraldry by A. C. Fox-Davies, p. 488