566 DR. J. W. EVANS ON MECHANICALLY-FORMED [Aug. 1900, 



is found along the western base of the Barda Hills, about 9 miles 

 north-east of Porbandar. The rock is exported from Porbandar 

 for building-purposes under the name of Porbandar Stone. 

 Specimens were examined by H. J. Carter, and described by him 

 in a paper read before the Bombay Branch of the Koyal Asiatic 

 Society in 1848 [3]. He assumed, without question, that it was 

 a subaqueous deposit ; see [5] A p. 313 & B p. 756. 



Mr. .Fedden, of the Geological Survey of India, states, in his 

 memoir on the geology of Kathiawar [9] p. 135, that the Porbandar 

 Stone is very thick and 



'occurs in three parallel ridges or ledges rising one above the other; it i& 

 white-coloured, and very obliquely laminated at an angle of about 22°, varying 

 in different quarries.' 



By the kindness of Mr. Chapman, I have had the opportunity of 

 examining a specimen (VI) of this rock. On treatment with acid, 

 less than 2 per cent, of insoluble material remains. This con- 

 sists, in addition to casts of small organisms, of a little angular 

 quartz and occasional flakes of felspar. In a thin section of the 

 rock no extraneous matter, except a few grains of quartz, was 

 visible. As will be seen from Mr. Chapman's paper, oolitic grains 

 have been found among the calcareous constituents of the rock. 



Mr. Fedden found somewhat similar deposits in other parts of 

 Kathiawar. He states [9] pp. 126-2S that the ' miliolite ' 



' forms the bluffs and cliffs on the south-eastern coast and extends some way 

 inland sheeting the surface of the country. ... In the eastern part of the 

 alluvial area it is seen only near the coast, while to the westward the whole 

 country is encrusted with the rock.' . . . 'The farther it occurs from the coast 

 the purer is the limestone, while that along the sea-board is not infrequently 

 mixed with much sand.' 



At Gopinath and Jaferabad it is iuterstratified with light cal- 

 careous sandstone. At the former locality some of the beds are 

 ' earthy and rubbly.' He records, on manuscript authority, that 

 Mr. Theobald in 1858 noted the occurrence in the rubbly beds of 

 two species of Bulimus, two of Helic, and one of Cyclotus. At 

 Motra Kotra ' grey softish ' calcareous sandstone occurs between 

 two beds of ' miliolite.' The sandstone, 



' though imbedded, is laminated obliquely in various directions after the manner 

 of blown sand, and it seems probable that much of the grey slightly coherent 

 sandstone consisted of blown sand in the form of dunes that became sub- 

 merged.' 



At Yerawal the ' miliolite ' passes laterally into an open, porous, 

 sandy rock, made up very largely of organic fragments and minute 

 organisms, resembling a raised beach in the vicinity. 

 The ' miliolite ' in the interior is stated to occur 



' capriciously in the gorges of the hills or as patches on their sides like remnants 

 of a snowdrift.' 



On Chotila Hill it forms a fringe round the truncated top, at a 

 height of 1173 feet above sea-level. 



Like Dr. Carter, Mr. Fedden had no doubt that the < miliolite ' 

 was throughout a marine formation ; see [9] p. 127. 



