tART 4.] 
ihule : Geulogy of NorlJi Arcot Dislricl. 
201 
Plants found. 
After mentioning a narrow and thin slip of hard ferruginous sandstone close 
to the ford bj which the Conjeveram-Wandiwash road 
Doshi outcrop. crosses the Pahir, Mr. Oldham describes the interesting 
outcrop at Doshi (a mile and a half to the south) thus:—“This locality and its 
immediate neighbourhood, though not affording even a single tolerable section, 
yielded to me the great majority of the fossil specimens, all plants, which I suc¬ 
ceeded in procuring from this series of beds.” “In a small tank west of the 
milage I noticed a little yellow sandstone in flat beds just appearing above the 
surface of the water when low, and from the bund of this tank, which is largely 
composed of the pieces of this and other beds thrown up when it was dug, I suc¬ 
ceeded in obtaining numerous plant remains.” “ I could not discover a trace of 
mollusca or other animal remains, birt in some of the beds of sandstone the plant 
remains are very abundant.” 
“ Until they have been more carefully examined and compared, I cannot attempt 
to do more than indicate their general character, which is 
very similar to that of the Rajmahal flora, presenting 
PalcBOzamia (Ptilophyllum), Tmniopteris ? Stangerites {Angiopteridium'), Pecopteris, 
and Sphenopteris.” “ I obtained also specimens of circinnate vernation of ferns. 
These remains occur in great abundance, principally in thin-bedded yellow sand¬ 
stones, but some of them also in a coarser thick-bedded sandstone.” “ This strip 
of sandstone has its limits narrowly defined by the appearance of gneiss in sihi 
closely on the east, north, and south, and at no great distance on the west also.” 
“About four miles west of Doshi is the best section seen of these beds. 
This is exposed in the old supply channel which i-uns from 
Mamdur section. riycr Palar near Umiaveram to the large Mamdur 
tank, in the banks of wliich and the small watercourse adjoining a fair section is 
exhibited, showing a greater thickness of beds than I was able to discover in any 
other locality.” “ Proceeding southward along the channel we get the following 
section. The first (lowest?) bed seen is a coarse white felspathic sandstone with 
small pebbles of qirartz, from 3 to 4 feet in thicknes.s, rather soft and scarcely 
consolidated, at least superficially. I could here detect no organic remains what¬ 
ever. Over these lie about 3 feet of a finer yellowish sandstone with minute 
shaly partings of a greyish-white color.” Above this are 5 feet of a hard 
ferruginous sandstone, the uppermost bed of which has a curiously tesse- 
lated appearance due to concretionary structure, assuming generally a penta¬ 
gonal arrangement. All these beds have a low dip(of 2° or 3° to the .south and 
south-south-west. “ Passing onward the section in the channel is broken and 
obscured by soil, &c., but the missing portion seems to be, at least in part, 
supplied by the smaller gullies, watercourses, &c., on either side, which show 
a few feet in thickness of yellow and white sandstone apparently overlying the 
ferruginous bands and dipping south-by-west at an increasing angle. Pro¬ 
ceeding still southward along the channel, we come upon a hard brown ferrugin¬ 
ous sandstone dipping south-south-west at 32°. Of this only 2 feet appear, and 
over this from 20 to 25 feet of a soft rather coarse yellow sandstone with 
a few harder ferruginous partings, all dipping south-south-west at from 30° to 36°. 
Over this with a dip in the same direction, but at gradually decreasing angles. 
