Among the rarest of all the congenital anomalies of the eye is peripapillary staphyloma or scleral ectasia, in which a normal or nearly normal optic nerve head lies at the bottom of a deep excavation in the fundus. This condition must be distinguished from coloboma of the optic disc, in which the defect is within the abnormal nerve head itself, 1 and myopic conus, in which the defect is usually temporal to the disc and progressive, and in which the nerve head is abnormal. 2 Zimmerman 3 first described the anomaly in a living dog which had pigmented arcs on both corneas, a peripapillary staphyloma in the right eye, and a staphyloma temporal to the disc in the left eye. Microscopic sections of the right eye showed the thin scleral ectasia to be lined with remnants of retina and choroid. The optic nerve was slightly atrophic, with increase in the