82 GUIDE TO THE FOSSIL REPTILES, AMPHIBIANS, FISHES. 
W all-cases 
6 - 7 . 
Table-cases 
1 1 , 12 . 
collection by fine specimens from the Old Eed Sandstone of 
Scotland (Wall-case 5), and by more fragmentary remains 
from England, Eussia, North America, and Greenland (Table- 
case 11). Its pectoral fins are as acutely lobate as in 
Fig. 84. —Restoration of Holoptychius flemingi, from the Upper Old Red 
Sandstone of Dura Den, Fifeshire; one-eighth nat. size. (After R. H. 
Traquair. Wall-case 5.) 
Ceratodus, and its large overlapping scales are rounded, with 
a wrinkled ornamentation. Its teeth, as shown in transverse 
section (Eig. 85), are of a very complex structure, much 
resembling that observable in the teeth of Labyrinthodonts 
Fig. 85. —Transverse section of tooth of Holoptychius, showing complicated 
“dendrodontstructure ; much enlarged. (After C. H. Pander.) 
(p. 47). This fish lived in shoals which were sometimes 
suddenly destroyed and buried, as shown by a remarkable 
slab of Old Eed Sandstone from Dura Den, Eifeshire, framed 
between Wall-cases 5, 6. Osteolepis (Eig. 86), Dijolopterus, 
