From time to time and under a variety of terms there has been discussed in the literature and at meetings of most of the American dermatologic societies a rare ulcerative cutaneous lesion, the specificity of which in relation to one or more of the usual pyogenic organisms is as yet not settled. Nevertheless, it has for many years been tentatively classified with ulcerative pyodermas. Ulcers of this kind have several clearcut clinical characteristics which I think distinguish them from certain other conditions. They have a tendency to persist and progress and to have undermining borders which develop as they progress and a tendency to recur after apparent cure, either in the same or in another locality. In a general way they are syphiloid, so much so that many of the patients are given long courses of antisyphilitic medication before the observer concludes that the condition is a resistant syphilid or