SIGNS 



fx = the Greek mu, which indicates micromillimeters, one of which equals 

 .001 of a millimeter or 1/25,400 of an inch. 



mm. = a millimeter or 1000 tx. 



cm. = a centimeter or 10 mm. 



§ = subgenus. 



- = dash between extreme measurements. 



X = used between numbers representing length and breadth. 



