In a recent report,1two cases of bulging of the squamous portion of the temporal bone in young children were described by me which were due to an underlying tumor of the temporal lobe found at operation. One was the result of a meningeal fibroblastoma with cystic formation; the other, of a gliomatous cyst. The latter, by displacement of the midline structures, had produced a milder degree of bulging in the opposite squama. In one case, therefore, the bulging was bilateral; in the other, unilateral. My object in this report is to record and discuss three instances of bulging of the squamous portion of the temporal bone observed in young adults, aged from 23 to 28, in each of which an underlying tumor was found at operation. In two patients, evidence of organic nervous disorder was present in childhood. REPORT OF CASES Case 1. —Bulging of the squamous portion