 The text on the 10-sentimo coin for the scientific name of the Philippine goby was minted as ""Pandaka pygmea" instead of ""Pandaka pygmaea", and the 50-sentimo coin showing the Philippine eagle misspelled the scientific name as ""Pithecobhaga jefferyi"" instead of ""Pithecophaga jefferyi"".In 1985, some of the 1-peso and 25-sentimo coins had a double strike error.In 1991, the "Improved Flora and Fauna Series" was introduced.