The Paleozoic Age 172. The period is placed inside the quotation marks. Put the period inside the quotation marks. The exclamation point is used to mark an out-cry, and also an emphatic or ironical comment. The colon is used to mark a discontinuity of grammatical construction greater than that indicated by the semicolon and less than that indicated by the period.
Artists see all things purple.
A company publishing texts for use in secondary schools has the following sales procedure. The colon should be placed outside the quotation marks. For enumerations within a single sentence, observe the relative values of comma, semicolon, and colon. Within each item, as between them successively, punctuation is based on desire for emphasis.