362 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



diminutive exceptions, if exceptions they are to be called, the state- 

 ment holds good that between our ancient and our modern fauna the 

 agreement is not closer than generic. In the class of fishes, the 

 resemblance even to that extent is true only of one order, — the 

 Cycloidans ; while the other order, the Ganoidans, which have left 

 their horny and bony scales so abundantly in our rocks, have entirely 

 disappeared from our rivers and tanks. Of the class Mollusca, while 

 the genera Planorbis and A?npullaria, now so common in our pools, 

 are altogether absent from this deposit, Valvata and Physa, so 

 extensively represented in it, both in species and individuals, have 

 disappeared from the plains of Central and Southern India. Of the 

 six genera Melania, Paludina^ Limnceus^ Bulimus, Succinea, and 

 Unto, which are common to both ancient and modern India, the 

 diiferences between the recent and fossil species, especially in the 

 Pahidina and Limnccus, are very great. Of the former, we have 

 nothing at all so large as the P. BengaJensis of the East, or even the 

 P. vivipara of Britain. In the latter genus, none of our species 

 appear to have belonged to the inflated type, but they are generally 

 more on the model of the L. glaber, than that of the L. stagnalis 

 of our native country. 



Combining then these facts, on the one hand we have the total 

 dissimilarity between every species of our ancient and modern plants, 

 — the disappearance from our flora of several genera, if not of some- 

 thing higher — the difference in prevailing type between some of our 

 fossil and existing genera of molluscs, and the removal of others 

 entirely from our continents to regions most remote, — and lastly, a 

 still more decided transference among the orders of our fishes, — data, 

 which all point to the negative conclusion, that it is no newer tertiary 

 that can be compared with our freshwater deposit. On the other 

 hand we find generically, specifically, and individually an equality, to 

 say the least, between our Ganoid and Cycloid fishes, and a resem- 

 blance between our flora and that of the London Clay, — proofs which, 

 in my opinion, lead us on to the positive inference that among older 

 tertiaries the eocene formation is that with which our freshwater 

 deposit must be classed. Bronn, I perceive, assigned it to the era 

 of the continental molasse. Whether or not the statements above 

 made will be sufficient to show that this view is incorrect, it is not 

 for me to say ; at all events, the fossils, which we have contributed, 

 will enable others to decide. 



Extent of the Freshwater Formation. — The extent of this tertiary 

 freshwater formation throughout India is very great. In Capt. Sher- 

 w ill's recentlypublished Geological Map we find it laid down on the west 

 of Rajmahal on the Ganges. Following the same parallel of latitude, 

 we come to Rae near Narwar, about forty miles south of Gwaliur, 

 whence specimens of Physa were obtained by Mr. Fraser, formerly 

 Agent to the Governor General in the Sagar and Narbadda territories. 

 At Sagar itself organic remains were first discovered by Col. Sleeman, 

 afterwards described bv Dr. Spry, and more recently investigated by 

 Capt. W. T. Nicholls^of 24th Regt. M.N.I. East of Jabbalpur, 

 in the same territories, occur the sites Suleya, where Dr. Spilsbury 



