In the last few years some unusual stone objects have been added to the Australian Museum collection. They are of two main types-stones bearing longitudinal and criss-cross incisions, and stones, generally waterworn pebbles, upon which is engraved a design or figure. Four (PI. iii, figs. 1 to 4) are pieces of sandstone of varied colouring, and scored across with parallel or converging incisions, such as might be made in sharpening pointed implements. They were found upon a coastal midden at Boat Harbour, near Sydney, by Mr. J. Ashley. Photographs were taken and coloured replicas made of the specimens, as the original pieces remain in the possession of the finder. A yellow sandstone artifact (PI. iii, fig. 1), scored on three surfaces by 10, 5 and 15 lines respectively. The dimensions are 13.8 cm. long, 10.2 cm. wide, and 4.5 cm. at the thickest part. A light grey sandstone (PI. iii, fig. 2) with roughly parallel scorings, 7 on one surface and 6 on the other. It is 13.2 cm. long, 9.2 cm. wide, and 3.75 cm. thick, and appears to be portion of a larger specimen. Pale yellow sandstone (PI. iii, fig. 3) with 2 deep incisions on one surface only. The length is 14 cm., width 13 cm., and thickness 2.7 cm. A reddish ferruginous sandstone (PI. iii, fig. 4), irregular in shape, and marked on one surface only by 7 grooves. It is 14.9 cm. long, 11.8 cm. wide, and 3.2 cm. thick.