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The presence of rhyolites in the Panjal traps at Panthachuk was first brought to notice by late Prof. K. K. Mathur. The author studied the Panjal traps in some detail and as a result the acid rocks have been found to occur at two other places also, viz., at Cheshmashahi and Avantipur. These acid volcanic rocks are of the nature of rhyolites, trachytes and dacites and are very clearly different from basic volcanic rocks like andesites and basalts. These rocks are fairly abundant and must have played an important part in the Panjal volcanic activity. [ABSTRACT FROM AUTHOR]

The physical, chemical and microscopic changes brought about by the intrusion of a mica-peridotite dyke in the Dishergarh seam have been investigated. The vitrain bands show distortion, folding and fading of lustre. Near the contact the coal is converted into 'jhāmā' which shows columnar structure. The chemical characteristics of the coal show more rapid changes on approaching the dyke. The coal has been affected up to a distance of 8 feet from the contact or slightly beyond, but is practically unaltered at a distance of 11 feet. The microstructures of fusain have not been affected. Vacuoles and cracks appear in the vitrain bands which increase in number and size as the dyke is approached. These are now filled with secondary mineral matter. [ABSTRACT FROM AUTHOR]

The forms described under the name Ontheostrobus sessilis come, as the name indicates, from Onthea. Most of the specimens show well preserved elongated receptacles bearing throughout their length numerous crowded seeds. The seeds are sessile and placed in shallow cupules which in turn are seated on cushions, the cushions being sessile on the receptacle. The receptacles from which the seeds have fallen off, show the exposed surfaces of the cushions slightly hollowed out. A small pit in the centre of this hollow marks the position of the vascular supply of the seeds. The detached seeds, usually found crowded together in their original groupings, show an elliptical scar at their chalazal end; this marks the area of attachment of the seeds with the receptacle. It is a noteworthy feature that not a single seed shows its micropylar end. [ABSTRACT FROM AUTHOR]

The interesting forms described in this paper under the new generic name Beaniopsis were found at Onthea in the Rajmahal Hills. Most of the specimens show well preserved female cones with distant sporophylls attached alternately to the cone axis by means of slender stalks. The stalk of the sporophyll is straight and like the cone axis its surface is longitudinally wrinkled. The distal end of each stalk is spoon shaped and bears two seeds on its upper surface. The exact mode of attachment of the seeds is not quite clear and must remain unsettled till better preserved material is found. Usually the seeds are placed in such a manner that the median lines marking the principal planes of the two seeds lie in continuation with each other and in the same plane as the long axis of the sporophyll stalk. The seeds are somewhat almond shaped with the base rounded and cordate, and the micropylar end is elongated and flattened. The micropylar ends of the seeds in a pair diverge from each other at a wide angle. The genus is evidently a gymnosperm and the only groups to which a relationship can be suggested, with the present data in hand, are the Cycadales and less probably the Ginkgoales. [ABSTRACT FROM AUTHOR]