COEEESPONDENCE. 



93 



which affords those of Stagonolepis, by the Rev. G. Gordon, of Birnie, and 

 is noticed in a note to a paper on the sandstones of Elgin by Sir Roderick 

 Murchison, also published in the fifteenth volume of the ' Geological 

 Journal.' It is supposed to have been a Saurian reptile, of from 6 to 8 feet 

 in length. 



Besides these, numerous slates covered with reptilian footprints are from 

 time to time dug from the neighbouring quarries of Cummingstone. 



The sandstones containing these remains were originally believed to be- 

 long to the upper division of the Old Red Sandstone series, and are de- 

 scribed as such by Sir R. Murchison in the paper above referred to. In 

 the note to that paper, however, it is remarked that, in consequence of the 

 high organization of these reptiles, and their affinity to those found in 

 Mesozoic strata, and as the stratigraphical relation of these sandstones with 

 the undoubted Old Red Sandstones of Elgin cannot, from overlying soil, be 

 positively determined, there is considerable reason to suppose that they may 

 belong to a more modern epoch ; and since that time they have been looked 

 on by most geologists as Triassic. The question of age has again been 

 opened up lately by the discovery of footprints similar to those of Cum- 

 mingstone in saudstones, believed to be Old Red, in Ross-shire. At present 

 it would premature to give any opinion as to the true position of these 

 reptiliferous sandstones ; but, as this is being very carefully wrought out 

 by well-qualified parties, it is to be hoped that a short time will suffice 

 finally to set at rest this qucsstio vexata. Jas. Powbie, F.G.S. 



Resioallie, February 12, 1863. 



Analysis of Red Chalk. 



Dear Sie, — The article on the above subject, by R. Calvert Clapham, 

 Esq., in the ' Geologist ' for January, 1863, p. 29, will no doubt have been 

 read with pleasure by geologists taking interest in such matters, more 

 especially those who study the chemical properties of the two strata 

 mentioned in the article above alluded to. At the same time I beg to refer 

 Mr. Calvert Clapham to a paper on the Red Chalk of England, by the 

 Rev. T. Wiltshire, in the ' Geologist ' for 1859, p. 161. In speaking 

 of the analysis of the Red Chalks of Speeton and Hunstanton, Mr. Wilt- 

 shire states that "one of the members of the committee of the Geologists' 

 Association, Mr. Rickard, has been good enough to make me an analysis. 



" The Speeton is as follows : — 



Carbonate of lime, with a little alumina 8T2 



Peroxide of iron 4 3 



Silica 145 



100 



From Hunstanton — 



Carbonate of lime 82 3 



Peroxide of iron 6 4 



Silica 113 



100 



The above results of Mr. Rickard are nearly the same as those pro- 

 duced by Mr. Calvert Clapham. The latter gentleman seems to have paid 

 more minute attention to the minor contents of the substances analysed. 



