Ungual lesions of psoriasis occur often enough to be worthy of serious consideration. When the process as a whole ceases to progress and no new ungual damage appears, an average minimum of one hundred and twenty days is still required for existing blemishes to grow out and be cut off. Ungual changes are among the most conspicuous of conditions affecting the cutaneous appendages and may be of great aid in the diagnosis of psoriasis. One of the most notable features of psoriatic nails observed in the series of cases to be reported has been the changes in color, which will be emphasized later. LITERATURE One of the most interesting early references to psoriatic ungual changes appeared in Willan's1 treatise on cutaneous diseases in 1809: The Psoriasis Unguium sometimes occurs alone, but it is usually connected with scaly patches on the arms, hands, etc. In some cases, the nails from