特551 臺灣貝殼郵票（第4輯）

• Sp.551.1
  
  quantity : 1,000,000
• Sp.551.2
  
  quantity : 900,000
• Sp.551.3
  
  quantity : 900,000
• Sp.551.4
  
  quantity : 900,000

• Sp.551.1a
  
  
• Sp.551.2a
  
  
• Sp.551.3a
  
  
• Sp.551.4a