Amalarius of Metz, was a Bishop and liturgical commentator on the various Western Orthodoxritual ordines; he lived in the late 700s and mid 800s, reposing around 850. Dumbarton Oaks has published an English translation of his most well-know work in two volumes; however, here we are concerned with the "Lost Work" of Amalarius.
Amalarius is probably most famous [and controversial in his own lifetime] for his heavy allegorical interpretations of all rites and customs. However, for our purposes, it is not the allegorical interpretation that is of interest, but, the fact that he records the actual rites and customs, with good detail.
The Henry Bradshaw Society, most well-known for publishing early Western liturgical texts, has recently published the text, "A Lost Work by Amalarius of Metz: Interpolations in Salisbury, Cathedral Library, MS 154", as Volume 2 of their Subsidia series. It is from this we shall be taken excerpts.