The Dipneusti and Crossopterygii 



305 



often large size of some species, all indicate morphological 

 advance over those of the lower rocks. 



Fig. 48. Eustlienopteron foordi, a crossopterygian fish from the 

 Upper Devonian of Scaumenac Bay, Canada. Letters indicate con- 

 stituent head bones. About one-sixth natural size. (After Whit- 



In the Upper Old Red — or Upper Devonian — possibly 

 even in the Mid-Devonian of eastern North America — of 

 Scotland, Belgium, Russia, of eastern Canada, and of the 

 North East United States some or all of the above genera 

 are found. The celebrated Dura Den beds of east Central 

 Scotland, those of Nairn and Elgin in N. Scotland, and the 

 Devonian beds of Russia, early furnished rich material 

 for study by Miller, Agassiz, and Eichwald, while the more 

 recent discoveries of Lohest, Newberry, and Whiteaves 

 in Belgium, Eastern America, and Canada respectively, 

 have materially extended our knowledge of the series. 



Traquair has also pointed out that the Nairn and the 

 Elgin beds, which are at or near the summit of the series, 

 represent two distinct faunal areas of deposit. The former 

 contains Holoptychiiis decoratiis, along with Psammosteus 

 tesellatus, AsteroJepis maximiis^ Polyplocodiis leptognathus, 

 and Coccosteus magnus; while the latter contain Holopty- 

 chiiis nobilissimus, H. giganteiis, H. decoratiis, Glyptopo- 

 mus minor, Sauripterus crassidens, along with Psammost- 

 eus taylori, P. pustulatus, Cosmacanthus malcolmsoni, Both- 

 riolepis major, Phyllolepis concentrica, Conchodus ostreae- 

 formis etc. He then states that "palaeontologically the 

 Nairn beds may be compared with those of Wenden in 

 Russia; the Elgin strata with those of the Sjass of the same 

 country." 



Hull has indicated (75:255) that the Kiltorcan beds 

 of South Ireland show close affinity with the upper Scottish 



