OF THE ASTEROLEPIS. 23 



Sir Roderick, on his return from his great Russian cam- 

 paigns, in which he fared far otherwise than Napoleon, and 

 accomplished more, submitted to Agassiz a series of fragments 

 of these gigantic Ganoids ; and the celebrated ichthyologist, 

 who had been introduced little more than a twelvemonth be- 

 fore to the PiericMhys of Cromarty, was at first inclined to 

 regard thera as the remains of a large cuirassed fish of the 

 Cephalaspian type, but generically new. Under this impres- 

 sion he bestowed upon the yet unknown ichthyolite, of which 

 they had formed part, the name ChelonichthySj from the re- 

 semblance borne by the broken plates to those of the cara- 

 pace and plastron of some of the Chelonians. At this stage, 

 however, the Russian Old Red yielded a set of greatly finer 

 remains than it had previously furnished ; and of these, casts 

 were transmitted by Professor Asmus of the University of 

 Dorpat to the British and London Geological Museums, and 

 to Agassiz. " I knew not at first what to do," says the ich- 

 thyologist, " with bones of so singular a conformation that 1 

 could refer them to no known type." Detecting, however, 

 on their exterior surfaces the star-like markings which had 

 misled Lamarck, and which he had also detected on the lesser 

 fragments submitted to him by Sir Roderick, he succeeded in 

 identifpng both the fragments and bones as remains of the 

 same genus ; and on ascertaining that M. Eichwald had be- 

 stowed upon it, from these characteristic sculpturings, the 

 generic name Asterolepis, or star-scale, he suffered the name 

 which he himself had originated to drop. Even this second 

 name, however, which the iclithyolite still continues to bear, 

 is in some degree founded in error. Its true scales, as I shall 

 by and by show, were not stelliferous, but fretted by a pecu- 

 liar style of ornament, consisting of waved anastomosing ridges, 

 breaking atop into angular-shaped dots, scooped out internally 

 like the letter V; and were evidently intermediate in their 

 character between the scales which cover the Glyptolepis and 



