PART 2.] Mallet: Mud volcanoes of Rdm.ri and C-hedmlja.. 
petroleum-bearing rocks occur througlioiit the islands, and that the oil-bearing 
rocks of Pegu, which are within 70 miles of Ramin in a straight line, are believed 
bj Mr. Theobald to be nunimulitic, all the known oil localities being situated 
either on nummnlitic or still younger strata. 
Again, the coal hitherto found in Eastern India (Assam and Burma) is all 
either of cretaceous or of nummulitic age, the former being markedly different 
in external characters from the latter.^ That from the Ramri Islands bears 
no resemblance to cretaceous coal, and is quite of the nummulitic type.® 
The number of mud volcanoes distributed over the islands is consid- 
1 enable, there being in Ramri itself a dozen or more : 
more than half that number in Cheduba®; three, 
at least, on Amherst, and two on Flat Island. I have heard of others on the 
neighbouring part of the mainland, but have no definite information about them. 
On the opposite side of the Airakan Range, near Menbo, on the Iirawadi, numer¬ 
ous mud volcanoes exist, M'hich have been described by Dr. T. Oldham^^ and 
two are mentioned by Mr. W. Theobald as occurring- on the coast not far from 
Cape Regrais.® I myself observed a very small one in the Baranga Islands, 
and there are records of two sub-marine eruptions. It was reported, on native 
infoi-mation, that two volcanoes opened in the Chittagong Di.strict during the 
earthquake of 1762.® It would appear, therefore, that salses are rather widely 
distributed over both flanks of the Arrakan Range. But those in the Ramri 
group hold the first place in magnitude and in the violence of their paroxysmal 
eruptions. It will bo observed that they illustrate, on a small scale, that di.stri- 
bution into linearly arranged and isolated vents which has been so commonly 
remai-ked amongst the great volcanoes of the earth. At Kyauk Phyu six occur 
in a line within a distance of perhaps a mile and a half along the summit of a 
low broad iddge. Two volcanoes in close proximity, or with their circumferences 
even touching each other, occur in several cases elsewhere. 
In respect to their form the volcanoes may be divided into mounds and cones. 
General appearance. l^owever, no sharp line between the two 
varieties. The former are approximately circular, 
generally varying in diameter from 50 to 100 yards with a height of perhaps 15 
to 30 feet; there are, however, two exceptionally large one.s in Gheduba, south-east 
of the Pagoda Hill, respectively about 200 and 250 yards across. The mounds looh 
like an accumulation of angular fragments of rock—shale, sandstone, &c., but this 
appearance is deceptive. During ordinary times mud is ejected in small quantities, 
and during the greater eruptions, stones and mud are shot out together, the whole 
f(jrming a sort of unconsolidated conglomerate. The wash of rain, however, scours 
' Memoirs, Vol. VII, p. 175. 
^ The limestone at Yaiitlick and Tsinbok (p. 221) apparently closely resembles that de-scribect 
by Mr. Theobald at p. 313 of bis report, and which he considers to be cretaceous. ITiat some of 
the Itamri rocks should bo refeiTed to this ag'e is by no means improbable. 
* Vide Captain Ilalsted’s Map, Journ. As. Soc., Bengal, Vol. X, p. 446. 
'* Mission to the Court of Ava; by Captain Vulc, 1855Appendix, p, 33U, 
■' Mem., Ci. S. 1., Vol. X, p. IIP. 
‘ .lourn. As. Soc., Bengal, XII, 1050, and I’hil. Trans,, LIIl, 231. 
