In Carboniferous and Permian Epochs 143 



the Lower Limestone as in considerable part marine, the 

 Edge coal as freshwater, the Upper Limestone as in part 

 freshwater, in part marine, the Coal Measures as almost 

 wholly freshwater. But in order to discuss this question 

 more intelligently, there is appended the lisf given by 

 Traquair of the entire fish-fauna of the Edinburgh rocks. 



From the subjoined list (p.p. 144-45) it will be seen that 

 while elasmobranchs are most largely confined to the "Low- 

 er" or "Upper" Limestone, that are accepted as marine, 

 Acanthodes sidcatus is common to the freshwater Burdie- 

 house and Dunnet shale ; Tristychius arcuatus is reported 

 from the Burdiehouse and Wardie shales, but also from the 

 Upper Limestone; several occur in the Edge Coal and 

 Upper Limestone; Sphenacanthiis serriilatus and Cyno- 

 podius crenulatus in the freshwater Burdiehouse, Dunnet, 

 and Edge Coal deposits, but also in the marine Upper 

 Limestone. 



But more remarkable is the list of crossopterygian and 

 accipenseroid forms, for Rhizodus hibberti — a most typical 

 freshwater species is also recorded from the Lower and 

 Upper Limestone. The same is true of Elonichthys robi- 

 soni, Nematoptychius greenocki and Eurynotus crenatus, 

 all common and typical freshwater fishes of the Edinburgh 

 Calciferous rocks, But it should most importantly be ob- 

 served here that all of the above species come either from 

 the "Gilmerton Ironstone" beds of the Lower Limestone 

 Series, or from the "South Parrot Coal shale" of the Upper 

 Limestone Series, both of which are freshwater beds inter- 

 calcated amid what are mainly true marine limestones. 

 Traquair however gives a list of what had now become 

 either anadromous or wholly marine fishes (op. cit. p. 

 693) as follows: 



Cladodus mirabilis Copodus planus 



Cladodus striatus Psammodus rugosus 



Petalodus acuminatus Cochliodus contortus 



Ctenoptychius lobatus Xystrodus striatus 



Ctenoptychius serratiis Poecilodus jonesii 



Petalorhynchus psittacinus Psephodus magnus 



Polyrhizodus magnus Acondylacanthus jenkinsoni 



Pristodus falcatus Harpacanthus fimbriatus. 



