APPENDIX. 
153 
position in the sand caused them to be sent home, under an 
idea that they were petrified roots.* Neither the insulated 
concretions from Ava, nor those adhering to the bones, 
contain traces of any kind of shell ; they also differ minc- 
ralogically from all the specimens of tertiary and fresh¬ 
water strata in this collection. 
Among the most remarkable of these strata is a fresh¬ 
water deposit of blue and marly clay, containing abun¬ 
dantly shells that belong exclusively to a large and thick 
species of Cyrena; a dark-coloured slaty limestone, con¬ 
taining shells, which Mr. Sowerby has identified with some 
of those that occur in our London clay. There is also, 
from the hills opposite Prome, granular yellow sandy lime¬ 
stone, containing fragments of marine shells, and much 
resembling the calcaire grossier of the environs of Paris; 
and from the same neighbourhood, and other places higher 
up the Irawadi, are several specimens of soft and greenish 
sandstones resembling those of our plastic clay formation. 
From all these, it appears highly probable, that some of 
the most important component members of our tertiary 
strata occur along a great part of the course of the Ira¬ 
wadi, between Ava and Prome, near which latter place 
the alluvial delta begins, which extends from thence, by 
Rangoon, to the Gulf of Martaban. 
Throughout this district also we seem justified, by the 
notes of Mr. Crawfurd, in establishing the existence of the 
* Dr. Fitton, in his excellent account of some geological specimens 
from the coasts of Australia, (London, 1826,) describes many similar 
examples of stalactite-shaped and other irregular calcareous con¬ 
cretions, in the sandy strata that occur on many parts of those coasts. 
He also gives references to authors who have described similar cases 
in other countries; viz. to Dr. McCulloch, who has described them 
as existing in Perthshire, Dr. Paris in Cornwall, Captain Lyon in 
Africa, and other writers. 
