Geological Society. 447 



are many fragments of ivory, derived probably also from the mas- 

 todon. 



The remains of the mastodon are by far the most abundant in this 

 collection, and amount to about 150 fragments. 



Of the rhinoceros there are about 10 fragments. 



Of a small species of hippopotamus, 2. 



Of the hog, 1 j and of the ox, deer and antelope, about 20. 



Of the gavial and alligator, about 50. 



Of the emys, 20 j and trionyx, 10. 



One fragment of emys is so large, that the animal of which it 

 formed a part, must have been several feet in width. 



The state of preservation of these bones is very perfect, from their 

 being penetrated with hydrate of iron, and thereby rendered strong. 

 Not one of them is silicified, though they have been erroneously 

 stated to be so, in some of the periodical journals. 



The district in which they were found is a little North of the town 

 of Wetmasut, and is composed of barren sand-hills and beds of gravel 

 intersected by ravines, and cemented occasionally into a breccia by 

 carbonate of lime, and sometimes by hydrate of iron. Over the sur- 

 face of these hills were scattered the fragments of bones and wood, 

 some quite naked and loose, others half buried in the sand and gravel. 

 Many fragments of wood lay also at the bottom of the ravines. 

 About one-third of the bones have been slightly rolled j and the rest 

 had all been broken before they were lodged in the places where Mr. 

 Crawfurd found them, and where they appear to have been dispersed 

 and buried, by the action of the same waters that produced the dilu- 

 vial sand and gravel, whence they have since been washed out, and 

 left bare by the action of rains and torrents. 



Concretions of sand and gravel adhere to many of the bones, but 

 they contain no traces of shells, and differ mineralogically from all 

 the rock specimens in this collection, which we recognize as belong- 

 ing to tertiary and freshwater strata. 



Indications of freshwater formation were found in one spot only, 

 not far from the fossil bones, and they consist of a marly blue clay, 

 abounding with shells of a large and thick species of Cyrena. 



The tertiary rocks are : 1st, a dark slaty limestone, containing 

 many shells, that have been identified by Mr. Sowerby with those of 

 the London clay. 2nd, a yellow sandy limestone containing shells, 

 and resembling the calcaire grossier, and 3rd, a soft greenish sand- 

 stone resembling the sandy beds of our plaslic clay formation. 



This London clay and calcaire grossier afford an additional locality 

 of these strata to those indicated by the specimens described by Mr. 

 Colebrooke, in vol. i. Part 1 , 2nd series of the Geological Transactions, 

 — which had already established the existence of this formation in 

 the N.E. border of Bengal. 



Mr. Crawfurd states distinctly, that it is impossible to refer the si- 

 tuation of the bones, or the origin of the hills containing them, to any 

 operations of the existing river : these hills are sixty feet above the 

 level of its highest flood ; the effect of its actual operations, he ob- 

 serves also, is distinctly visible in the shifting islands of mud and sand 



that 



