Ia.—Iowa.

Ib. or ibid.—Ibidem, in the same place.

Ich.—Ichthyology.

Ictus.—Jurisconsultus.

Id.—Idem, the same.

Id. T.—Idaho Territory.

i.e.—Id est, that is.

I. H. S.—Jesus hominum Salvator, Jesus the Saviour of men.

ij.—Two, (med.)

Ill.—Illinois.