8 Mr. A. S. Woodward on the 



Incertce seclis. 



Genus LOPHOSTRACON. 



Lophostracon sjntzhercfense (Lankester). 



1884. Lophostracon spitztjergense, E. R. Lankester, op. cit. p. 5, pi. ii. 

 fig. 6. 



The ribbed fragment of dermal armour thus named by 

 Lankester still remains incertce sedis ; but two new facts may 

 be added to the original notice. In the first place, when light 

 is allowed to fall upon the impression of the superficial orna- 

 ment in a certain direction the ridges are distinctly shown to 

 have been crimped or tuberculated. The published figure is 

 thus not quite accurate. Secondly, the tissue of the plate is 

 coarsely cancellated, and numerous irregularly arranged bone- 

 lacunai can be distinguished in microscopical sections. 



It must be remarked, however, that the Spitzbergen 

 Lopliostracon is not unique. So long ago as 1837 Kutorga * 

 described and figured similar fossils from the Lower Devonian 

 of Livonia, erroneously regarding them as referable to a 

 Chelonian under tlie name of Trionyx sulcatus. Twelve 

 years later, also, Hugh Miller f figured another example 

 from the Old Eed Sandstone of Thurso, Caithness, as a 

 " shoulder {{. e. coracoid ?) plate of Asterolejnsy All these 

 fossils probably pertain to a large Arthrodiran fish ; and they 

 occur upon the same horizon as the genera Homosteus and 

 Ileterosteus . 



Form, and Loc. The only known specimen was obtained 

 by Dr. Nathorst from the Red Sandstone of Dickson Bay. 



Genus Poeolepis, nov. 



Syn. Gyrolepis, G. Kade (non Agassiz), Programm k. Realschule zu 

 Meseritz, 1858, p. 17. 



An imperfectly recognizable genus, known only by detached 

 rhomboidal scales. Scales moderately imbricating, with a 

 feeble inner ridge, and not united by a peg-and-socket articu- 

 lation ; the exposed surface covered with punctate ganoine 

 and in the antero-superior half marked with oblique wrinkles 

 and ridges. 



The distinctness of these scales from those of any known 

 genus was first recognized by Kade, who described examples 



* S. Kutorga, Beitr. Geogn. u. Palaont. Dorpat's, pt. ii. (1837), p. 13, 

 pi. ii. figs. 1-4. 



t H. Miller, ' Footprints of the Creator ' (1849), p. 88, fig. 38. 



