FROM THE TERTIARY BEDS IN THE ISLAND OF BOMBAY. 7 



soil of tlie swamps, before the muscular and ligamentary parts of the 

 body could decompose. Most likely, volcanic action and the flows of 

 lava streams were the agents wliich caused the rapid destruction of the 

 little life that existed in their neighbourhood. Storms and winds were also 

 most likely in operation then as they are now, for some of the specimens 

 give direct indications on the rock that they have been dragged along the 

 surface of the soft mud for various distances (see fig. 6 on pi. IX) . The fine 

 stripes on the surface, the tracks which the body left on it, — being a little 

 deeper where they correspond to the thickened joints of the body, — are dis- 

 tinctly traceable. No force acting on a special part of the body of the froo" 

 could produce this, for it would have certainly dislodged the correspondino- 

 position of the various bones. It could have been only one which acted 

 upon the whole body equally strongly, without injuring any part of it, and 

 that was apparently only the motion of the atmosphere. The surface of the 

 rock is generally smooth, and only occasionally appears so little disturbed 

 that it would seem more difficult to explain the dragging motion of the 

 dead specimens by a temporary upheaval of the strata. Besides, if such 

 had been the case, the motion of the specimens would most likely be a 

 more general one, while in reality the marks (see fig. 6) appear to be 

 rarely found, and are certainly not traceable on six other specimens of 

 the same species of frog, lying on the same surface of the slab beside the 

 one figured. 



Eor further geological details, I must refer the reader to Mr. Wynne^s 

 interesting account of these deposits in his paper on the geology in the 

 Island of Bombay, (loc. cit., p. 217, etc.). 



Explanation of Plate IX. 



Fig. 1. A complete skeleton, drawn to double the natural dimensions ; dorsal view. 



Fig. 2. Ventral view of the head, the first three vertebra, humerus and breast 

 bones ; drawn to twice the natural dimensions. 



Pig. 3. Upper view of the exact form of the head, drawn in three times of the 

 natural dimensions. 



( 393 ) 



