A rare form of familial dystrophy of the corneal epithelium was described clinically by Pameijer1in 1935. In 1938 Meesmann2studied this dystrophy pathologically and found an abundance of glycogen in the corneal epithelium. Although other authors have described this dystrophy,3-6none has identified conclusively as glycogen the deposits which Meesmann reported. The purpose of this communication is to report a case with histochemical and finestructural studies and to suggest a possible pathogenesis of the disease. Report of Case The propositus was a 31-year-old white female, who was first seen in the clinic of the Massachusetts Eye and Ear Infirmary in September, 1961. She had been sent on referral for diagnosis of "black spots" of unknown duration in the cornea. Her only subjective complaint was occasional ocular irritation. Vision with correction for myopic astigmatism in each eye was 20/40-2 OD and 20/60 OS. The corneas were studded