1. A type of bony sclerosis is described, occurring in nine members of a Jamaican family and resembling the more benign form of Albers-Schönberg's disease. The parents were consanguineous. Three of the patients developed facial palsy at the same age, and one had bilateral optic atrophy and proptosis.

2. Although radiological changes occurred of all grades of severity, certain features often described in this condition were lacking. In one child the onset of radiological changes was observed at the age of eleven years.

3. Serum studies showed increased alkaline phosphatase activity.

4. These features are discussed in the light of present-day knowledge and theory of the pathology of Albers-Schönberg's disease.