AGNATHA. 
59 
Asterolepis and Bothriolepis seems to have been naked. Well- Table-cases 
Dy E. 
Fig. 54.—Restoration of Pterichthys milleri , upper (A), lower (B), and left 
side-view (C), from the Middle Old Red Sandstone of Scotland ; about 
one-half nat. size, a, anconeal; a.d.l. anterior dorso-lateral; a.m.d. 
anterior median dorsal; a.v.l. anterior ventro-lateral ; ag. angular; 
ar. articular ; c. central of lower limb; e.l. extra-lateral or operculum; 
l. lateral; l.occ. lateral occipital; m. marginal; m.occ. median 
occipital; m.v. median ventral; ran. mandibular plates (displaced 
backwards in the drawing) ; p.d.l. posterior dorso-lateral ; pm. 
premedian; p.m.d. posterior median dorsal; p.v.l. posterior ventro¬ 
lateral ; pt.m. post-median ; s.l. semi-lunar ; t. terminal. (After 
R. H. Traquair. Table-case D.) 
preserved examples of Bothriolepis canadensis, from the 
Province of Quebec, are especially noteworthy. 
