CLASSIFICATION OF DEVONIAN FISHES. 



9 



There can be no doubt that the scales of GlyptolGpis possess the 

 ornamentation here represented. Not only does Professor Pander 

 positively state that the scale figured by him was worked out from 

 a Lethen Bar nodule, and formed part of the unquestionable 

 Glyptolepis represented in his Plate 7, fig. 4 ; but the specimen of 

 Glyptolepis leptopterus represented by Agassiz in the " Yieux Gres 

 Rouge," Tab. 21, fig. 2, and now in Sir Philip Egerton's collection, has 

 obviously sculptured scales and cranial bones. And I find that by 

 scraping away the inner layers of the scales of undoubted examples 

 of this genus, in the Museum of Practical Geology and in that of the 

 Royal College of Surgeons, the points and ridges of the sculpture 

 remaining imbedded in the rock are easily displayed. The clear 

 recognition of the fact that this elegant structure really characterizes 

 Glyptolepis is of great importance, for, in the first place, it enables 

 one to discriminate between Holoptychius (whose scales have no 

 semilunar area of backwardly directed points) and Glyptolepis, and, 

 in the second place, it places beyond a doubt the justice of Professor 

 Pan der's conclusion that the scale figured by Miller in the " Footprints," 

 as appertaining to Asterolepis, really belongs to Glyptolepis. 



Pander states that the rays of the median fins are supported 

 upon long interspinous bones, and that the paired fins are very 

 much approximated ; the ver}^ long pectorals extending far beyond 

 the bases of the ventrals, which are very broad and strong. 



Specimens which I have examined show, that the parietal bones 

 of Glyptolepis are large, and, like the frontals, distinct from one 

 another ; in their form and relative proportions, these bones very 

 much resemble those of Holoptychius. There are three bones in the 

 superior occipital region, one median and two lateral. A trian- 

 gular, single or divided, squamosal fits in between the parietal, the 

 external of the three superior occipital bones, and some indistinctly 

 defined supratemporal and postorbital plates ; again, as in Holo- 



FlCr. 7. 



Restoration of Glyptolepis. 



