• Species: Illosporiopsis christiansenii (B.L. Brady & D. Hawksw.) D. Hawksw.
• Remark: earlier under Hobsonia christiansenii B.L. Brady & D. Hawksw.
• Fungus type: lichenicolous
• Treatment in Estonia: certain

• Species: Illosporium carneum Fr.
• Remark: see: Pronectria robergei (= name of the teleomorph)
• Fungus type: lichenicolous
• Treatment in Estonia: synonym

• Species: Imshaugia aleurites (Ach.) S.L.F. Meyer
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain
• hall terasamblik

• Species: Intralichen christiansenii (D. Hawskw.) D. Hawksw. & M.S. Cole
• Remark: earlier under Bispora christiansenii D. Hawksw.
• Fungus type: lichenicolous
• Treatment in Estonia: certain

• Species: Intralichen lichenum (Diederich) D. Hawksw. & M.S. Cole
• Remark: earlier under Bispora lichenum Diederich
• Fungus type: lichenicolous
• Treatment in Estonia: certain

• Species: Ionaspis carnosula (Arnold) Arnold
• Remark: see: Hymenelia carnosula
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Ionaspis heteromorpha (Kremp.) Arnold
• Remark: see: Hymenelia heteromorpha
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Ionaspis rhodopis (Sommerf.) Blomb. & Forssell
• Remark: see: Hymenelia rhodopis
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Japewia subaurifera Muhr & Tønsberg
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain

• Species: Karsteniomyces peltigerae (P. Karst.) D. Hawksw.
• Remark: see: Scutula miliaris (Wallr.) Trevis.
• Fungus type: lichenicolous
• Treatment in Estonia: synonym

• Species:
• Remark:
• Fungus type:
• Treatment in Estonia: