Joseph was the oldest son of Samuel Medlicott, rector of Loughrea, and his wife Charlotte, daughter of Colonel H.B.
Together, the brothers mapped the line separating the Vindhyan and Gondwana rocks along the valleys of the Narmada and Son Rivers.
It is suggested that Medlicott left the Survey around 1861-62 (possibly because siblings in the same department were discouraged) and worked in Bengal.
He was married to Agnes and they had a son Samuel (born 1860) who moved to British Columbia where he died in 1900.
[2] It has been suggested that Medlicott's work was plagiarized years later by William Dixon West to whom some credit the discovery of the Narmada Sons Lineament.