CALAMODENDRON. 



13 



A portion of one of the specimens of fossil wood on analysis^ gave 



Carbonate of lime ... ... ... ... 76*66 



Carbonate of magnesia ... ... ... ... 12*87 



Sesquioxide of iron ... ... ... ... 4*95 



Sulphate of iron ... ... ... ... ... 0'73 



Carbonaceous matter ... ... ... ••. 4'95 



The stratum lying immediately above the seam of coal in which the specimens occurred 

 generally termed the " roof," was composed of black shale, containing large calcareous 

 nodules, and for a distance of about two feet six inches upwards was one entire mass of 

 fossil shells of the genera Goniatites, Orthoceras, Aviculopecten, and Posidonia. 



The beds in the vicinity of the coal occurred in the following order, namely, 



1. Black shale, with nodules containing fossil shells 



2. Upper seam of coal, enclosing the nodules full of fossil wc 



3. Fire-clay floor, full of jS^j^-mana., . 



4. Clay and rock 



5. Lower seam of coal 



6. Fire-clay, full of Stigmaria. 



The fossil wood occurred in spherical, lenticular, ; 

 nodules, varying from an inch to a foot in diameter ; 

 the round and globular specimens being in general 

 small, whilst the flatter nodules were nearly always of a 

 large size. No fossil shells were met with in the nodules i. 

 found in the coal itself (" 3"), although, as previously stated, 2, 

 they were very abundant in the nodules found in the roof ^■ 

 (" 1") of the seam,which there rarely contained any remains 

 of Plants. The large nodules of ten to twelve inches in diameter, when they occurred, 

 swelled out the seam of coal both above and below, as in the annexed woodcut, fig. .2. 



Yds. Ft. In. 



0 2 (; 



0 0 6 

 0 2 0 

 2 0 0 

 0 10 



0 



nd elongate and flattened 



Fig. 2. 



§ 3. Remarks on No. 3 Specimen. 



The third specimen intended to be described in this Memoir is from a small seam 

 of coal, about two feet in thickness, in the Lower Coal-measures, and marked ** in the 

 vertical section at p. 12 ; and is from the same seam that the specimen of SigUlaria 

 vascularis described by me in the paper published in the ' Quarterly Journal of the Geo- 



^ For this analysis I am indebted to the kindness of Mr. Hermann. 



