“…LEGENDRE (1963) attributed to Westring (1843) the first description of a feature with such probable function in Theridiidae, but the first audible sound was reported for spider by WOOD-MASON (1876) for the Indian theraphosid Chilobrachys stridulans (Wood-Mason, 1875). Up to now, several features were described and classified in tarantulas as stridulatory organs (for revisions see CHRYSANTHUS, 1953;LEGENDRE, 1963;UETZ & STRATTON, 1982). In fact, these organs were widely used in the systematics of Theraphosidae (POCOCK, 1895(POCOCK, a, b, 1897(POCOCK, , 1899SIMON, 1903;PÉREZ-MILES et al, 1996;SCHMIDT, 1999SCHMIDT, , 2000.…”