1 he rock in wliicli tbe Upper Devoniaii fish-remains occur 

 in East Grreenland is a fine-grained, dark reddish-brown 

 sandstone, occasionally mottled by small patcbes of argilla- 

 ceons material. It bas an irregular fracture, and cannot be 

 distingnisbed from tbe sandstone wbicb contains Holoptycliius 

 in tbe Catskill Formation of Pennsylvania and in tbe Upper 

 Old Red Sandstone Series of Pertbsbire. All tbe fossil re- 

 mains are fragmentary, consisting only of detacbed scales, 

 dermal plates, and rarely a tootb. Tbe two typical Upper 

 Devonian genera, Holoptychms and AsteroUpis^ are, bowever, 

 elearly recognisable. 



I. Holoptychiiis nobilissimus, Ag. Figs. 1—10. 



Tbe numerous scales of Holoptychius seem to rej)resent 

 all parts of tbe body, varying in sbape from tbe deeply- 

 ovate form cbaracterising tbe middle of tbe flank, to tbe 

 circular and elongate-ovate forms peculiar to different parts 

 of tbe caudal region. All of tbem are more or less imper- 

 fectly sbown, owing to tbe manner in wbicb tbe prominent 

 external ornament adberes to tbe matrix. It is sometimes 

 difficnlt to determine wbetber tbe ridges are smootb or nodose; 

 wbile tbeir relative tbickness cannot always be recoguised in 

 tbe fractured specimens. 



Tbe largest deeply-ovate scales, represented only by frag- 

 ments (nos. 1, 2), measure from 0'05 m. to 0-06 m. in tbeir louger 

 or vertical diameter. On tbe block of sandstone no. 1, tbe 

 greater part of tbe inner face of one of tbese scales is ex- 

 posed, proving tbat it is destitute of a median tubercle, as 

 usual in Holoptychius. On tbe same block, tbere are imperfect 

 impressions of tbe outer face of otber equally large scales, 

 displaying numerous irregularly wavy ridges, wbicb con- 



