This description of the Arundina Serpentina, or Serpent Candlestick, can be found in Archdale King's Liturgies of the Primatial Sees, p. 224. It was the equivalent in the Rite of Braga of the old pre-1955 tripartite candle used during the Easter fire. I have never much missed the tripartite candle, until I read about this:

...is of considerable interest, as it takes the traditional form of a bronze winged dragon on a pole, with the three candles issuing from the mouth of the dragon.

King notes below, on pp. 281-282:

The use of a dragon or serpent as a candlestick for the tripartite candle was very general in the middle ages.

The Regularis Concordia (c. 965-75) prescribed its use at the blessing of the new fire on the three days of the Triduum Sacrum: 'On Maundy Thursday, after none, a procession went down to the church door, bearing with it a staff which ended at the top in the shape of a serpent. There, fire, struck with a flint, was first hallowed, and then used for lighting a candle which came out of the serpent's mouth. From this all other candles were ighted; and the same ceremonial was repeated on Good Friday and Easter Eve. A serpent figured also in the ceremonies of the three days in the Abbey of St. Mary at York. Here the blessing of the fire took place in the chapter house, and on the Thursday the sacristan in an aparelled alb walked first cum hasta habente serpentem in sumitate tres cereos affixos candelabro in ore ejus non accensos. On Good Friday, the serpent was carried by the prior, and on Holy Saturday by the principal chaplain of the abbot.

A rubric in the Mozarbic Missale Mixtum says that in the procession to the font on Holy Saturday: Hic exeat subdiaconus cum cruce hoc ordine: Ceroferarii cum cereis pergant coram cruce; et cereus paschalis coram cereis, et serpens coram cereo, et sic procedant ad fontem ordinatem. The Liber Ordinarium makes no mention of a 'serpent,' and the device was almost certainly borrowed from the Roman-Toledan use existing in the primatial church in 1500. [...]

The ordinarium of the Church of Bayeux, compiled at the end of the 13th century, refers to the bearer of the tripartite candle as the draconifer: Draconifer in suppelliceo et capa serica, et habeat draco in ore candelas plures retortas.

Okay, that settles it. I want to be a draconifer and wear a surplice and silk cope. Restore the arunda serpentina! Or at the very least, it might be adapted to make a nifty Paschal Candle stand.

Incidentally, on the subject of the defunct tripartite candlestick or trident, a few photos of it can be found at the website of S. Clement's Episcopal, Philly. Somehow, I'm not that surprised.