The Tetras was a bronze denomination within the Sicilian Greek system corresponding to 4 onkia - or one third of a Litra. 
The tetras was denoted by four pellets on the reverse.
The tetras was denoted by four pellets on the reverse.

                    (1)
                                Agyrion
                            
                
                
                 
                
                
                
                
                                Obverse: crude head of Ares or Athena right wearing crested Attic helmet
                            
                            
                                Reverse: club; AΓYPI / NAIΩN
                            
                            
                            Diameter: 
                                19.5 mm
                            
Die Orientation: -
Weight: 6.9 g
                            
                        
                        
                        Die Orientation: -
Weight: 6.9 g
No notes for this coin
                        
                                Campana 11; CNS III, 20 OS; SNG ANS -; HGC 2, 54
                        
                    
                    (2)
                                Akragas
                            
                
                
                 
                
                
                
                
                                Obverse: eagle right, tearing at hare AKP_A
                            
                            
                                Reverse: Crab, crayfish left below •••
                            
                            
                            Diameter: 
                                21 mm
                            
Die Orientation: -
Weight: 9.21 g
                            
                        
                        
                        Die Orientation: -
Weight: 9.21 g
No notes for this coin
                        
                                SNG COP. 75 var. SNG München 132
                        
                    
                    (3)
                                Solus
                            
                
                
                 
                
                
                
                
                                Obverse: head of Athena half left wearing Corinthian helmet
                            
                            
                                Reverse: warrior kneeling right, drawing bow, shooting arrow; KPRA (kapara meaning village)
                            
                            
                            Diameter: 
                                15 mm
                            
Die Orientation: -
Weight: 2.3 g
                            
                        
                        
                        Die Orientation: -
Weight: 2.3 g
No notes for this coin
                        
                                cf. Calciati I pg. 310, 5 (same); SNG ANS 743.
                        
                    