THE OLD RED SANDSTONE OF THE ORKNEYS. 



423 



The Cromarty, Achanarras, and Stromness Beds. 



The third group of fossils recognised by Dr Traquair is that which Hugh Miller first 

 described from Cromarty, and he himself, on several occasions, from Achanarras 

 (Caithness), and which was long believed to be the only one present in the Orkneys. 



The following is a list of the fossils of Cromarty, Achanarras, and the Stromness beds 

 of Orkney . — 



Palceo spondylus Gunni, ..... 









A. 





Diplacanthus striatus (Ag.), .... 







C. 



A. 



0. 



,, tenuistriatus (Traq.), 







C. 







Rhadinacanthus longispinus (Traq.), . 







c. 



A. 



0. 



Mesacanthus pusillus (Traq.), . . . . . 







c. 



A.? 



0.? 



Cheir acanthus Murchisoni (kg.), . 







c. 



A. 



0. 



„ lotus (Egert.), . . . . . 







c. 







„ grandispinus (M'Coy), 











0. 



Pterichthys Milleri (Ag.), 







c. 



A. 



0. 



„ productus (Ag.), .... 







. c. 



A. 



0. 



„ oblongus (Ag.), ..... 







c. 



A. 





Dipterus valencienisii, (Sedgw. and Murch.), 







c. 



A. 



0. 



Coccosteus decipiens (Ag.), ..... 







. c. 



A. 



0. 



Homosteus Milleri (Traq.), ..... 







c. 



A. 



0. 



Glyptolepis paucidens (Ag.), .... 









A. 



0. 



„ leptopterus (Ag.), .... 





. 



c. 





0. 



Gyroptychius microlepidotus (Ag.), 







c. 



? 



0. 



Diploplerus Agassizi (Traill), .... 







. c. 



A. 



0. 



Osteolepis macrolepidota (Ag.), .... 







c. 



A. 



0. 



Cheirolepis Trailli (Ag.), ..... 







c. 



A. 



0. * 



A glance will show the very complete accordance of these lists. All the more 

 frequently occurring fishes are common to all the localities, except possibly Glyptolepis 

 paucidens (Ag.), which in the Cromarty district is replaced by the closely allied 

 Glyptolepis leptopterus (Ag.). Gyroptychius microlepidotus (Ag.) seems to be absent 

 from the Caithness area. The other fishes found in one area only are all rare fossils. 



If, now, we examine the list to ascertain which fossils are confined to these areas, we 



find that — 



Palwospondylus Gunni (Traq.) 



Diplacanthus, 2 sp. 



Pterychthys, 3 sp. 



Cheirolepis Trailli (Ag.) 

 and possibly 



Gyroptychius microlepidotus (Ag.) 



are not known to occur elsewhere. 



* This list has been compiled from— Traquair, " Fossil Vertebrates of the Moray Firth " ; Traquair, " Achanarras 

 Revisited"; A. S. Woodward, British Museum Catalogue of Fossil Fishes. 



VOL. XXXIX. PART II. (NO. 13). 



3 S 



