The numbers 176-177 are omitted in paging.
One of the 12 plates mentioned in the title (the "map of the country of the savage nations, intended to be put, facing page 72") was reserved for publication with a second volume, which was, apparently, never published, although the author states in the "Advertisement" at end of v. 1 that v. 2 "is now in the press."
The "two whole sheet maps" were published separately, with date 1774. For a description of this chart of the coast of East and West Florida, see A list of maps of America in the Library of Congress, 1901, page 281.
Description based on online resource; title from PDF title page (LLMC Digital, viewed October 5, 2016)