Currently, only one species, Trichoplax adhaerens, is acknowledged to belong to the Placozoa. The Italian Francesco Saverio Monticelli described another species in 1893, which he found in the waters around Naples, naming it Treptoplax reptans.
A standard mallet has a head length of 9 to 9.5, and this is recommended for beginners. Expert players may use longer head lengths up to 12, as this is thought to make aiming more accurate and makes it harder to accidentally twist the mallet during the stroke.
A basic croquet set consists of 6 hoops, 1 peg, 4 mallets and 4 balls coloured red, black, yellow and blue. Optional extra's include 4 hoop clips of matching colour to indicate the next target for each ball, a small mallet for hammering the hoops and peg into the ground, 4 corner flags and 8 corner pegs to mark the ends of the 4 yard-lines.