Size and Shape:

Size varies from 0.2 - 60 µm. 
There are 4 basic shapes - spherical, rods, spiral and square.

 
 
 Spherical is called coccus.
 Division along the same plane forms chains; 2 cocci together - Diplococcus
 4 - 20 in chains - Streptococcus.
 Division along 2 different planes - 
  Tetrads
 Division along 3 planes regularly - 
  Sarcinae
 Division along 3 planes irregularly - 
  Staphylococci
Copyright 1996 by the Faculty Resource Center

Sylvester McKenna & Devabrata Mondal
Long Island University, Brooklyn Campus