4(>8 Geological Society: — 



pose of reducing the readings of the absorption-bands to wave- 

 lengths a graphical method was employed, the details of which are 

 given in the paper. This method appears to be one of general 

 applicability for the plotting of spectra. 



Tables then follow giving the wave-lengths of 66 bands of 

 each absorption-spectrum ; and a map accompanies the text, in 



o 



which the bands are drawn to a scale one half that of Angstrom's 

 " Spectre Normal." 



A careful comparison of these Tables and of the map shows that, 

 although both spectra contain a large number of lines which are 

 nearly coincident, the spectra as a whole are not identical, either 

 when the vapours are examined at high or low temperatures, or 

 when the lengths of the columns of absorbing gas are varied. 



GEOLOGICAL SOCIETY. 

 [Continued from p. 397.] 



June 21, 1876.— Prof. P. Martin Duncan, M.B., E.P.S., President, 

 in the Chair. 



The following communications were read : — 



5. " On the Discovery of Plants in the Lower Old Red Sandstone 

 of the Neighbourhood of Callander." By E. L. Jack, Esq., E.G.S., 

 and E. Etheridge, Jun., Esq., E.G.S. 



6. "On an adherent Form of Procluctus and a small Spiriferina 

 from the Lower Carboniferous Limestone Group of the East of 

 Scotland." By P. Etheridge, Jun., Esq., E.G.S. 



7. Notice of the occurrence of remains of a British fossil ZeugTodon 

 (Z. WanMyni, Seeley) in the Barton Clay of the Hampshire coast." 

 By Harry Govier Seeley, Esq., E.L.S., E.G.S. 



8. "On the remains of Emys hordwellensis, from the Lower 

 Hordwell beds in the Hordwell Cliff." By Harry Govier Seeley, 

 Esq., E.L.S., E.G.S. 



9. " On an associated Series of cervical and dorsal Yertebr8e of 

 Pobjpty chodon from the Cambridge Upper Greensand." By Harry 

 Govier Seeley, Esq., E.L.S., E.G.S. 



10. " On Crocodilus icenicus (Seeley), a second and larger spe- 

 cies of Crocodile from the Cambridge Upper Greensand." By Harry 

 Govier Seeley, Esq., E.L.S., E.G.S. 



11. " On Macrurosaurus semrm.s (Seeley), along-tailed animal with 

 proccelous vertebrae, from the Cambridge Upper Greensand." By 

 Harry Govier Seeley, Esq., E.L.S., E.G.S. 



