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.
This is often seenon plain tile roofs when they arebeing stripped and retiled.Plain tiles traditionally use2.65mm aluminium clout head nailsoriginally used with 32mm widebattens. Now that all battens usedfor plain tiles should be 38mm wideand 25mm deep a 3 or 3.35 mmdiameter clout head nail should beused.