Data on the silver coins and silver discs recovered from the 1554 Plate Fleet, Padre Island, Texas

Enlargement of a typical Late Series (1545-1572?) Details of Carolus-Johanna silver coin, 4 reales denomination, to show details of obverse and reverse sides.
Obverse Side: Crowned Shield of Carolus I of Spain (Charles V of the Holy Roman Empire. Devices of the different kingdoms of Spain -- Castles of Castile in the upper left and lower right quadrants, Lions Leon in the upper right and lower left quadrants, Pomegranate of Granada at bottom of shield. Note all are kingdoms the Queen Isabella was ruler of. No symbolism of King Ferdinand is present.
M - mint mark for Mexico City
L - assayer mark, in this case, that of Luis Rodriques, the next to the last of the assayers (R,G,F,P - for the early series- not shown; and G, A, R, S, L, O.
Legend around obverse side of coin - CAROLUS : ET : JOHANNA : REGES --- literally, Carolus and Johanna Rulers

Reverse Side: Legend continues - +HISPANIARVM : ET : INDIARUM -- literally -- Spain and the Indies
CENTER OF COIN - Crowned Pillars of Hercules with waves signifying the Atlantic Ocean. The Pillars of Hercules represented the Straits of Gibraltar . At the base of the pillars are waves which represent the Atlantic Ocean. Above the waves is the number 4, which represent the denomination of 4 Reales ( There are also 2 Realer represented by two dots.) A limited number of 3 reales were minted in the Early Series.
Hapsburg Family Motto across pillars of Hercules - PLUS ULTRA , which literally translated is "There is More". This is a take off of a legend that Alexander the Great is said to exclaim, "I have conquered all , there is no more" literally -- "Non Plus Ultra"

Note all the crowns are opened crowns -- a "King Arthur type crown". A domed crown was to be used exclusively by the Holy Roman Emperor, signifying his dominion over the kings.

Silver stamps found on Silver Discs found on the 1554 Plate ships.

a-c - possible ownership marks. a & b are variations of shells-- possibly representing the Shell of St. James, and possibly represents church ownership.

d - e Tax Marks. a is the official tax paid mark with the Pillars of Hercules, and Carolus I's motto, "Plus Ultra. and M for Mexico City" By itself, it signifies that a 20% tax has been paid -- The King's Fifth."
b. Roman numeral X, representing that only a 10% tax was paid. When present, it is always found in combination with d.

f & h - mine marks -- both Tasco (present day Taxco) and Guachinango (Huachinango) were well established mining regions in the 16th century.

g & n - Assayer mark -- probably that of Luis Rodriques

Remaining marks are problematical owner's marks, with the AMATEPNQVE, being the most enigmatic.