The broad flat marshy heads of all the streams in the central and northern parts of the chain, and the rounded hills that separate them, indicate the levelling action of a tidal sea, acting on a low flat shore;[[371]] whilst the steep flat- floored valleys of the southern watershed may be attributed to the scouring action of higher tides on a boisterous rocky coast. These views are confirmed by an examination of the east shores of the Bay of Bengal, and particularly by a comparison of the features of the country about Silhet, now nearly 280 miles distant from the sea, with those of the Chittagong coast, with which they are identical.

[371] Since our return to England, we have been much struck with the similarity in contour of the Essex and Suffolk coasts, and with the fact that the tidal coast sculpturing of this surface is preserved in the very centre of High Suffolk, twenty to thirty miles distant from the sea, in rounded outlines and broad flat marshy valleys.

The geological features of the Khasia are in many respects so similar to those of the Vindhya, Kymore, Behar, and Rajmahal mountains, that they have been considered by some observers as an eastern prolongation of that great chain, from which they are geographically separated by the delta of the Ganges and Burrampooter. The general contour of the mountains, and of their sandstone cliffs, is the same, and the association of this rock with coal and lime is a marked point of similarity; there is, however, this difference between them, that the coal-shales of Khasia and limestone of Behar are non-fossiliferous, while the lime of Khasia and the coal-shales of Behar contain fossils.

The prevalent north-east strike of the gneiss is the same in both, differing from the Himalaya, where the stratified rocks generally strike north-west. The nummulites of the limestone are the only known means we have of forming an approximate estimate of the age of the Khasia coal, which is the most interesting feature in the geology of the range: these fossils have been examined by MM. Archiac and Jules Haines,[[372]] who have pronounced the species collected by Dr. Thomson and myself to be the same as those found in the nummulite rocks of north-west India, Scinde, and Arabia.

[372] “Description des Animaux Fossiles des Indes Orientales;” p. 178. These species are Nummulites scabra, Lamarck, N. obtusa, Sowerby, N. Lucasana, Deshayes, and N. Beaumonti, d’Arch. and Haines.

Chapter XXX

Boat voyage to Silhet—River—Palms—Teelas—Botany—Fish weirs—Forests of Cachar—Sandal-wood, etc.—Porpoises—Alligators—Silchar—Tigers—Rice crops—Cookies—Munniporees—Hockey—Varnish—Dance—Nagas—Excursion to Munnipore frontier—Elephant bogged—Bamboos—Cardiopteris—Climate, etc., of Cachar—Mosquitos—Fall of banks—Silhet—Oaks—Stylidium—Tree-ferns—Chattuc—Megna—Meteorology—Palms—Noacolly—Salt-smuggling—Delta of Ganges and Megna—Westward progress of Megna—Peat—Tide—Waves—Earthquakes—Dangerous navigation—Moonlight scenes—Mud island—Chittagong—Mug tribes—Views—Trees—Churs—Flagstaff hill—Coffee—Pepper—Tea, etc.—Excursions from Chittagong—Dipterocarpi or Gurjun oil trees—Earthquake—Birds—Papaw—Bleeding of stems—Poppy and Sun fields—Seetakoond—Bungalow and hill—Perpetual flame—Falconeria—Cycas—Climate—Leave for Calcutta—Hattiah island—Plants—Sunderbunds—Steamer—Tides—Nipa fruticans—Fishing—Otters—Crocodiles—Phœnix paludosa—Departure from India.

We left Churra on the 17th of November, and taking boats at Pundua, crossed the Jheels to the Soormah, which we ascended to Silhet. Thence we continued our voyage 120 miles up the river in canoes, to Silchar, the capital of the district of Cachar: the boats were such as I described at Chattuc, and though it was impossible to sit upright in them, they were paddled with great swiftness. The river at Silhet is 200 yards broad; it is muddy, and flows with a gentle current of two to three miles an hour, between banks six to twelve feet high. As we glided up its stream, villages became rarer, and eminences more frequent in the Jheels. The people are a tall, bold, athletic Mahometan race, who live much on the water, and cultivate rice, sesamum, and radishes, with betel-pepper in thatched enclosures as in Sikkim: maize and sugar are rarer, bamboos abound, and four palms (Borassus, Areca, cocoa-nut, and Caryota) are planted, but there are no date-palms.

The Teelas (or hillocks) are the haunts of wild boars, tigers, and elephants, but not of the rhinoceros; they are 80 to 200 feet high, of horizontally stratified gravel and sand, slates, and clay conglomerates, with a slag-like honey-combed sandstone; they are covered with oaks, figs, Heretiera, and bamboos, and besides a multitude of common Bengal plants, there are some which, though generally considered mountain or cold country genera, here descend to the level of the sea; such are Kadsura, Rubus, Camellia, and Sabia; Aerides and Saccolabia are the common orchids, and rattan-canes and Pandani render the jungles impenetrable.

A very long sedge (Scleria) grows by the water, and is used for thatching: boatloads of it are collected for the Calcutta market, for which also were destined many immense rafts of bamboo, 100 feet long. The people fish much, using square and triangular drop-nets stretched upon bamboos, and rude basket-work weirs, that retain the fish as the river falls. Near the villages we saw fragments of pottery three feet below the surface of the ground, shewing that the bank, which is higher than the surrounding country, increases from the annual overflow.