The purpose of this paper is to define further a little-known tumor of hair follicles and to show how it illuminates the origin of the nevoid class of tumors. By our criteria we have been able to find only two previous reports of one case each, first by Prinz1 and recently by Hyman and Clayman.2 These were titled hair-follicle nevi, a designation which we deem inappropriate. We shall add ten additional cases, only two of which were personally observed. The remainder were gathered from the consultant histopathology practice of one of us (H. P.). The cases will be presented as a group rather than in detail, for the histologic picture is strikingly pathognomonic and Hyman and Clayman's description cannot be exceeded for clarity. Besides our main concern is to fix the position of this tumor in the galaxy of benign adnexal neoplasms. Clinical Picture The tumor is not