Knowledge concerning the histologic construction of the generalized nevus is as yet imperfect. In the exact clinical and microscopic examinations of patients who come collectively for observation, one therefore encounters sometimes manifestations that are peculiar and in general even unknown, and that seem to correspond to definite clinical forms. That fact holds good also for the following communication. REPORT OF CASE Several years ago, a postal clerk, aged 60, appeared at the dermatological division of the Krankenhaus der Stadt Wien for an examination. He showed, as an incidental observation, a generalized unilateral keratotic nevus only slightly developed and extending over one half of the body (fig. 1). On the right side of the back, over the right shoulder and posterior axillary fold, in the loin and over the right half of the nates were seen nodules follicularly placed, partly in groups and partly single, and arranged lineally or in rows.