876 Scientific Intelligence. — Geology. 



thus accurately defined by the great naturalist Agassiz. — (Sir Ro- 

 derick Murchison's Address to the Royal Geographical Society, 

 vol. xxiii.) 



19. Geological conclusions in regard to the Russian Interior 

 Seas.— There is perhaps no feature of more commanding interest in 

 its bearing on the physical outlines of the earth at a period which 

 approaches near to our own era, than the fact, which geological re- 

 searches have established, that there has existed a vast interior sea, 

 which covered all the area between Constantinople on the west, and 

 Turkestan on the east, or a length of nearly two thousand miles, whilst 

 it ranged irregularly from south to north over a space broader than 

 the present Caspian Sea is long, or of about one thousand miles. Of 

 this great submerged area, the Seas of Azof, the Caspian, and the 

 Aral, are now clearly the chief detached remnants. For, as I for- 

 merly explained, the very same species of mollusca which are now 

 living in these seas, are found in a fossil state in limestones forming 

 cliffs on their shores, or on those of the Black Sea, or in masses ef 

 intermediate land, which are simply the elevated bottoms of a once 

 continuous vast internal sea, the whole of whose inhabitants were as 

 distinct from those of the then ocean as are the present inhabitants 

 of these detached Caspians from those of the present Mediterranean 

 and ocean. — (Sir Roderick Murchison s Address to the Royal Geo- 

 graphical Society, vol. xxiii., p. lxxxvii.) 



20. On the 'probable depth of the Ocean of the European Chalk 

 Deposits. By Professor H. D. Rogers (Prov. Bost. Soc. Nat. Hist., 

 1853, 297-) — Various geologists, and among them Professor Ed. 

 Forbes, in his excellent and learned Palaeontology of the British 

 Isles, in Johnston's Physical Atlas, have suggested that the ocean of 

 the chalk deposits of Europe was a deep one ; and in evidence of 

 this, Professor Forbes cites the " striking relationship existing to 

 deep sea form of the English Chalk Corals and Brachiopods, adding, 

 that the peculiar Echinoderms (Holaster, alerites, Ananchytes, 

 Cidaris, Brissus, and Goniaster) favour this notion, as also the pre- 

 sence of numerous Foraminifera." 



21. Professor Rogers' objections to Professor F orb es" 1 Deep- Sea 

 Genera. — I beg leave to present a difficulty in the way of this con- 

 clusion. Several of these genera of Echinoderms, as Ananchytes, 

 Cidaris, &c, occur in the greensand deposit of New Jersey, referable 

 by every fossil test to the age of the greensand and chalk of Europe. 

 And this American stratum was unquestionably the sediment of quite 

 shallow littoral waters. That they must have had a trivial depth 

 is proved by the circumstance that they repose in almost horizontal 

 stratification, at a level of not more than from one to two hundred 

 i'eet lower than the general surface of the hills and upland region to 

 the N.W. of the margin of the zone they occupy as their outcrop. 

 It is obvious that a depression of the cretaceous region, such as 

 would cover the present deposits with a deep sea, would have like- 



