When Gerard Krefft named the species in 1873, he intended to commemorate the man who first reported it to him, Australian Native Police officer and amateur naturalist Robert Arthur Johnstone (1843-1905).
Cando Gerard Krefft nomeou esta especie en 1873, pretendía homenaxear ao home que primeiro lle informou a el deste animal, o policía e naturalista australiano Robert Arthur Johnstone (1843-1905).