FIG. 74 



75 





Figs. 74-79. Pteraspis (restored). X \. (After LANKESTER.) Lower Old Red 

 Sandstone, Herefordshire. 75. Palcsaspis americana, Claypole. X 4. (Restoration after 

 CLAYPOLE, somewhat modified by the writer.) 76. Pteraspis, dorsal shield, slightly 

 restored. (After LANKESTER.) 77. Pteraspis, ventral shield (" Scaphaspis ") , showing 

 mucous canals. (After SMITH WOODWARD.) 78. Cephalaspis lyelli, side view. (Re- 

 stored by LANKESTER.) 79. Cephalaspis lyelli, dorsal aspect, x \. (After L. AGASSIZ.) 

 Specimen from Old Red Sandstone, Forfarshire. A C. Rhomboidal scales from different 

 body regions. B. Tessera from middle layer of head shield. 



66 





