The clauses were originally written in the wrong order, which doesn't help.
The underlined part, from maritus to filiae, is marked as an insertion after dicti defuncti. So I think this is how it works:
8o Dec: 1681
Will(el)mus Blunden ^pater naturalis & Guardian(us) Sarae Blunden Nepotis^ d(i)c(t)i def(unc)ti, maritus et conjunct' person' Joannae Blunden
alias Kelsey filiae [unicae - deleted], ac Legatarie in Testamento &c nominate
& ex(ecuto)ribus fiducie prius renuncian(tibus) ac Ad(ministra)tor &c cu(m) Tes(tamen)to
annexo &c [iure … Jurat' - all deleted] p(er) me Tho: Briggs
8 December 1681
William Blunden, the natural father and guardian of Sarah Blunden the granddaughter of the said deceased, [and] the husband and conjunct of Joan Blunden otherwise Kelsey, [who is] the [only deleted] daughter of the said deceased and a legatee named in the will etc., the executors having first renounced the trust, [is the] administrator etc., with the will annexed etc. By me Thomas Briggs