On two new species of Mesembrioxylon from the Vicinity of Pondicherry, South India

U P till now the published records of petrified woods from South India are rather scanty. Sahni (1931) described a few species of M esembrioxylon, viz. M. godaverianum (near Bogapalmila in the Godavari district), M. Schmidianum (near Tiruvakkarai), M. Parthasarathyi (near Vellum,S miles south of Sripermatur) and one undetermined species; two species of Cupressinoxylon, viz. C. coramandelinum (near Madras) and C. alternans (near Raghavapuram, Godavari district) ; and lastly a single undetermined species of Dadoxylon (near Uttatur, Trichinopoly area). During a tour of South India in December 1951, I had an opportunity to collect a large number of fossil woods near the village of Tiruvakkarai, 13 miles WNW of Pondicherry. The fossiliferous area gives the appearance of a petrified forest, containing gigantic fossil trunks some of which measure 35 to 50 ft. in length. The present paper deals with the structure of some trunks of woods, 4 to 8 ft. long and nearly 2 ft. in diameter. Concerning the geological age of the fossiliferous locality at Tiruvakkarai, Sahni ( 1931 ) says: "The way in which the fossils lie scattered on the ground often forming natural bridges across ravines which have been cut under them by streams of rain water suggests that they have been gradually washed out of the grits and left approximately in situ. There are, however, no water-worn surfaces or other evidence of the relics having been transported since fossilization, there can thus be no doubt that they are of the iame age as the rocks in which they are preserved. These Trivicary grits, as the rocks are locally named, belong to the Cuddalore series... The horizon is said to range from Eocene to Pliocene." On the basis of the material described in the present paper it is not possible to add anything to the view regarding the age of the fossiliferous beds. DESCRIPTION