He appears to be in Malden, Mass. in the 1880 & 1900 Census. See the first 3 results here:
http://www.rootschat.com/links/0ap6/ 1893 Malden, Mass. city directory
Bryant, Guy C., student, boards 15 Albion
1897 Malden, Mass. city directory
Bryant, Guy C., clerk (B.), boards 15 Albion
1900 Malden, Mass. city directory
Bryant, Guy C., rooms at 120 Salem
1906 & 1908 Malden city directories
Bryant, Guy C., clerk (86 Blackstone, B) home 81 Linwood -- the B after Blackstone probably stands for a nearby town, but I'm not sure what
WWI Draft Registration Card 12 Sep. 1918
Guy Caldwell Bryant
31 Milford St., Boston, Mass.
Age 43, born 13 Apr. 1875
White, native born
Occupation - freight handler
Employer - B and W Elest (?) Ft. Hlg. (?), 529 Common? St., Boston
Nearest relative - wife Mary Bryant, Provincetown, Mass.
Tall, medium build, grey eyes, brown hair