1858.] MURCHISON — SANDSTONES OF ELGIN. 439 



Table III. — Tahle of Fossil Fishes common to Scotland and Russia. 



Of the thirteen genera of Devonian Ichthyolites of Russia described for me 

 by Agassiz (see ' Russia in Europe,' vol. ii. p. 397 et seq.), twelve are common 

 to that country and the Scottish Old Red ; whilst of the tliirty species of these 

 genera, no less than eighteen are absolutely identical with our South and North 

 Scottish types. Now, as in Russia these Old Red fishes are found to be mixed 

 up with species of marine shells well known in Devonshire, the synchronism of 

 the formations in Devonsliire, Russia, and Scotland is established. 



Pterichthys major, ^^. Elgin; Findhorn; — Riga; Andoma. 



Bothriolepis (G-lyptosteus) favosa, A^. Clashbinnie ; Elgin ; — Russia (common). 



(G.) ornata, -4y. Monachty; Nairn; — Russia. 



Osteolepis major, Ag. Lethen ; — S. of Petersburg and Kokenhusen. 

 Diplopterus macrocephalus, Aff. Lethen ; — S. of St. Petersburg ; Priutchka. 

 Glyptolepis leptopterus, Aff. Lethen ; Caithness ; Dipple ; — S. of St. Petersburg. 

 Holoptychius nobilissimus, Ag. Clashbinnie ; Elgin ; — Priutchka. 



Ajidersoni, Ag. Dura Den ; — S. of St. Petersburg. 



Actinolepis tuberculatus, Ag. Findhorn ; — S. of St. Petersburg. 

 Plaiygnathus Jamesoni, Ag. Dura Den ; — S. of St. Petersbiirg. 

 Dendrodus latus, Owen. Findhorn ; — Riga. 



strigatus, Owen. Scat Craig, Elgin ; — Riga ; S. of St. Petersburg. 



sigmoides, Owen. Scat Craig, Elgin ; — S. of St. Petersburg. 



Lanmodus biporcatus, Ag. Elgin ; — Riga ; S. of St. Petersburg. 



Panderi, Ag. Elgin ; — Riga ; S. of St. Petersburg. 



Cricodus incurvus, Ag. Elgin ; — Riga. 



Asterolepis Asmusii, Ag. Elgin ; Caithness ; Orkney ; — Dorpat ; Riga. 



minor, Ag. Elgin ; — Riga ; S. of St. Petersburg. 



In Russia, beds containing the above-mentioned fossil fishes overlap both 

 Lower and Upper Silurian, including in the latter the equivalent of the Ludlow 

 Rock. As the mass of the Lower Old Red is wanting, there is nowhere in Russia 

 a complete transition from the Upper Silurian into the Old Red, as in Shrop- 

 shire and Herefordshire. In that typical Silurian tract of Britain, the geologist 

 observes a gradual passage from the Bone-bed and Downton Sandstone with a 

 few Ludlow fishes, through certain intermediate beds* into the base of the Old 

 Red with Cephalasj^is. 



* I will not ventm'e to say that some of the beds called by Pander Upper 

 Silm*ian (and which contain fishes closely allied to, if not identical with, Cejjiha- 

 laspis, Auckenaspis, or Fteraspis) may not be the equivalents of the passage-beds 

 above noticed. 



