THE Geological Department of Glasgow University has recently received from Dr. W. R. Smellie and Mr. J. V. Harrison some fossils collected by them which throw further light on the age of the limestones of the Persian arc at the north-western end of Luristan, about 100 miles north-east of Baghdad. The locality, Gilan, is on a tributary of the Diala, about 30 miles south-east of Kasr-i-Shirin, a well-known station on the main road from Baghdad to Teheran. The geology of this part of the Persian frontier has been investigated by J. de Morgan (Miss. Sci. Perse, vol. iii, pt. i, Étud. Géol., 1905, pp. 71–112), who has given a geological map (ibid., pl. xix) of an area about 60 miles south-east of Gilan. De Morgan has identified there a folded series of Cretaceous and Eocene limestones, with lacustrine and gypsiferous Miocene beds. The locality at which the fossils were collected by Messrs. Smellie and Harrison is in line with the strike of the rocks in the area of de Morgan's map.