170 



THE GEOLOGIST. 



escaping for ages into the upper air, was condensed, and fell in the shape 

 of snow and hail. By this mass of snow and hail the temperature of the 

 earth's climate was reduced from the comparative warmth which preceded 

 it, even in Arctic regions, and the world entered on ' the cold period,' which 

 it was the object of the lecturer to describe and to account for while de- 

 scribing. Professor Agassiz said that this was the winter which preceded 

 mans advent in the world " 



Is not my point made out ? Is not the thohu and vohu of Moses iden- 

 tical with the cold period, the winter of the tvorld, of Agassiz ? Surely there 

 can be only one answer. 



It seems almost superfluous to refer to the boulders which are found in 

 Norway and on the coasts of north-western Europe, which evidently be- 

 long to the period of the Drift, and which have been borne to the spots 

 where they are now found on moving ice. 



I think, Sir, your readers must allow that my point is clearly made out, 

 namely, that Moses and the geologists are of one mind as to the deplorable 

 condition of the earth at the time when the Mosaic record and geology 

 come in contact. I have the honour to remain, Sir, 



Your obedient servant, 



Fkedeeick Fysh. 



Walgrave, April 7, 1864. 



P.S. I take the meaning of the fourth day's creation to be, that the 

 sun, moon, and stars, which had been previously obscured, then became 

 visible. Henceforth the earth was to receive light from those luminaries, 

 and not to be supplied with miraculous light, as on the first day. 



The Scottish Pteraspis. 



Dear Sir,— If not occupying too much space, I would feel obliged by 

 your inserting in an early number the following remarks on the communi- 

 cations in your numbers for March and April from the Rev. H. Mitchell 

 and Mr. E. H. Lankester ; these I have the less hesitation in offering, as, 

 while fully appreciating the value of the criticisms of one who has done so 

 much towards adding to our knowledge of this genus as Mr. Lankester, I 

 can at same time fully corroborate the correctness of Mr. Mitchell's re- 

 storation, in his interesting letter, in almost every particular. 



In a former letter (Geol. Feb. 1863) I had occasion to remark that Mr. 

 Lankester, in a notice (Dec. 1.862) of a former and much less correct re- 

 storation of our Scottish Pteraspis by Mr. Mitchell (Nov. 1862), had not 

 made sufficient allowance for probable specific difference of form. I must 

 here state my belief that the same mistake has again occasioned some of 

 Mr. Lankester's remarks in his last letter. I had recently an opportunity 

 of inspecting Mr. Mitchell's series of specimens of this fish, and of com- 

 paring them with my own. They all undoubtedly belong to the same 

 species, and are in my opinion distinct from Pteraspis rostratus and other 

 English species. 



The only points in Mr. Mitchell's latter restoration which appear to me 

 scarcely correct are, that the breadth seems rather exaggerated, and that 

 the posterior margin is represented as formed of straight lines, while it 

 consists of a double curve, concave posteriorly. The lateral posterior 

 angles are produced, forming well-marked but very short cusps, pointing 

 backward and slightly outwards. From this and also from the well-marked 



