128 APPENDIX. 



covery of another marine stratum consisting of the siliceous epidermis of Diatomaceaa in such an un- 

 locked for locality, is of the greatest interest, and will, it is to be hoped, assist somewhat in deciding 

 the true position of such commonly called "infusorial earths." Its similarity to that found on the 

 Pacific coast of North America, would seem to point to its identity in time with that widely extended 

 stratum, and doubtless the results which we have a right to expect from the very complete survey of 

 the State of California, now being carried on, will shed much light on this point. Prof Toumey 

 placed the stratum of Virginia much lower than had been done by Prof Rogers, and the correctness 

 or incorrectness of his views in this respect and as bearing on the Californian and Japan deposits, can 

 only be demonstrated after a careful examination and comparison of the adjacent strata. It is desirable 

 that the layer extending from Petersburg in Virginia almost to Baltimore in Maryland, should be 

 examined by a competent observer, and its characters be carefully determined and noted so that they 

 can be compared with those of the Pacific. I hope, ere long, to be able to contribute something 

 towards that end, but extended suites of specimens will have to be collected before we can hope to 

 arrive at any very definite results. Meantime the discovery of such a stratum in Japan will lead to 

 searches for similar deposits in other parts of the world, and I trust and fully expect witb success. 



Respectfully yours, 



ARTHUR MEAD EDWARDS. 



