On some silicified woods from near Pondicherry, South India

THE paper deals with three new species of fossil woods of which one belonging to the genus M esembrioxylolt is coniferous and the other two dicotyledonous. All the three species have been collected from near a village called Murttanqi (or also as Mortandra) 5 miles W.N.W. of Pondicherry in the South Arcot district of Madras State. The fossiliferous locality is about 2-3 sq. miles in diameter and presents a very imposing view with its numerous petrified trunks lying irregularly scattered on the ground. Some of the trunks are found partially buried in the soil. Besides silicified trunks which dominate the landscape in this area, hardly any other organic remains are found; the only other fossils to be met with are some Gastropods. The whole fossiliferous area near Pond icherry is a plain, dotted with hillocks not more than 100 ft. high, with ridges, caves and ravines. The hillocks are formed of Cuddalore series, which are made up of argillaceous and silicified sandstones with lumps and veins of chert. The Cuddalore series belongs to the Tertiary, and so far nothing has been decided definitely about the exact age of these sandstones. They are believed to range from Eocene to Pliocene (SAHNI, 1931). Krishnan (1949) regards the Cuddalore series to be Miocene, while Wadi a ( 1952) considers a great part of this series to be of Pliocene age, and some parts younger. The series as a whole lies along the east coast and overlies the various coastal deposits of Mesozoic age. A variously shaded and mottled loose-textured gritty sandstone is the principal component of these rocks. The petrified trunks usually occur embedded in these sandstones, but many have been loosened by weathering and consequently lie scattered on the ground. The occurrence of M esembrioxylon, a podocarpaceous form-genus, appears to be very common in various rock formations of India (SAHNI, 1931; RAMANuJAM, 19531; BHAR-