Fig. 9. 



Fig. 10. 



Fig. 9. Pterichthys milleri Agassiz. Lower Old Red Sandstone; Scotland. Restored 

 outline of dorsal aspect, x I (after Traquair) . 



Fig. 10. The same from the ventral aspect. Lettering for both figures, and for Fig. 11: 

 to. oec, median occipital; I. occ, lateral occipital; ag., angular; pt. m., post-median; 

 p. m., pre-median; I., lateral; e.l., extra-lateral; m., median; o., ocular; mx., maxilla; 

 s.l., semilunar; a.m.d., anterior median dorsal; p.m. d., posterior median dorsal; 

 a. d. I., anterior dorso-lateral; p. d. L, posterior dorso-lateral; a. v. L, anterior ventro- 

 lateral; p. v. I., posterior ventro-lateral; to. »., median ventral; d. ar., dorsal articular; 

 v. or., ventral articular; e. m., external marginal; i. m., internal marginal; d. a., dorsal 

 anconeal; v. a., ventral ancoaeal; c.e., centrals of louver limb ; m. m. to. to., marginals of 

 lower limb ; t . , terminal of lower limb . 



Fig. 11. Pterichthys milleri Agassiz 



Fig. 11. 

 Restored outline of lateral aspect, x i (after Traquair) . 



