Agaricus praeclaresquamosus A.E. Freeman, 1979, is a replacement name in Agaricus for Psalliota meleagris Jul. Schäff. 1925 because of the competing synonym A. meleagris With. 1792.
It is pre-dated by the heterotypic synonym Agaricus moelleri Wasser, 1976, Type Denmark. Thus A. moelleri is the correct name for this European species.

Likewise Agaricus placomyces var. meleagris, also based on Psalliota meleagris, is another synonym of A. moelleri.

The name A. placomyces is misapplied in the USA for the taxon correctly called Agaricus deardorffensis - in California at least.