The author, William Stanley Owen of Penrhos, was an eminent Victorian archaeologist. Pitt-Rivers was married to his niece. The book is about his various excavations at the Ty Mawr settlement from 1862 which lay on his estate on Ynys Gybi (Holyhead Island).

Ty Mawr is in the TMA database called the 'Holyhead Mountain Hut Group' which I believe Jane, treaclechops and Moth visited on their recent expedition to Anglesey.
http://www.themodernantiquarian.com/site/3353

The goodies found were split between the British Museum and his own museum called Ellin's Tower on Ynys Gybi near his stately pile. The stuff in Ellin's Tower has since been 'mislaid'.

He also published his excavation reports on this site in Archaeologia Cambrensis.