PLATE III. 



Fig. Page. 



Ampyx drummuckensis, sp. nov. 18. 



1. Head-shield, nearly perfect, showing frontal and genal spines and coarse punctation of 



surface where shell is removed, x 2. Drummuck. Mrs. Gray's Collection. (Figured by 

 Nicholson and Etheridge, ' Mon. Silur. Foss. Girvan,' fasc. ii, p. 178, pi. xiii, fig. 1, as 

 Ampyx rostratus.) 



2. Head-shield and portion of thorax, showing length of frontal spine. X 2. Drummuck. 



Mrs. Gray's Collection. 



3. Head-shield, imperfect, showing two pairs of pits at sides of glabella and one pair near 



base. Surface of cast shows coarse punctation. x 2. Drummuck. Mrs. Gray's 

 Collection. (Figured by Nicholson and Etheridge, op. cit., fasc. ii, p. 178, pi. xiii, figs. 

 2, 2 a, as Ampyx rostratus.) 



4. Pygidium, showing segmental and tuberculated axis and smooth lateral lobes, x 2\. 



Drummuck. Mrs. Gray's Collection. (Figured by Nicholson and Etheridge, op. cit., 

 fasc. ii, p. 178, pi. xiii, fig. 3, as Ampyx rostratus.) 



5. Completely enrolled individual, showing pygidium and head-shield in contact, thorax, etc. 



X 2h Drummuck. Mrs. Gray's Collection. 



Ampyx depressus (Angelin). 17. 



6. Head-shield, showing faint nodules at base of glabella and grooved frontal spine. X 6. 



Whitehouse Bay. Mrs. Gray's Collection. 



7. Ditto, x 6. Whitehouse Bay. Mrs. Gray's Collection. 



Ampyx hornei, Etheridge, jun., and Nicholson. 19. 



8. Head-shield, perfect, showing tubercle and lateral lobes of glabella and radiating lines on 



cheeks, x If. Balclatchie. Mrs. Gray's Collection. (Figured by Nicholson and 

 Etheridge, ' Mon. Silur. Foss. Girvan,' fasc. ii, p. 184, pi. xiii, fig. 6.) 



9. Ditto, x 2. Balclatchie. Mrs. Gray's Collection. (Figured by Nicholson and Etheridge, 



op. cit., fasc. ii, pi. xiii, fig. 4.) 



10. Portion of thorax and pygidium. x 2. Balclatchie. Mr. Gray's Collection. (Figured by 



Nicholson and Etheridge, op. cit., fasc. ii, pi. xiii, fig. 7.) 



Ampyx macallumi, Salter. 21. 



11. Nearly perfect individual, showing head-shield with grooved frontal spine, faint nodules at 



base of glabella, thorax, and pygidium. X 2. Dow Hill. Mrs. Gray's Collection. 



12. Pygidium, showing trilobed axis and curved pleurae on lateral lobes, x 3. Dow Hill. 



Mrs. Gray's Collection. 



Ampyx mammillatus, Sars (?). 22. 



13. Head-shield, nearly complete, showing rounded frontal spine, one pair of pits, and oblique 



furrows on glabella. X 5. Balclatchie. Mrs. Gray's Collection. 



Ampyx mammillatus, var, austini, Portlock (?). 23. 



14. Head-shield, imperfect and slightly crushed, showing two pairs of furrows on the glabella. 



X '21. Ardmillan. Mrs. Gray's Collection. 



Ampyx cf. foveolatus, Angelin. 23. 



15. Head-shield, neai-ly perfect, showing short broad cheeks, prominent broad glabella, with 



oblique angulated furrows, faint basal nodules, and rounded frontal spine. X 2|. 

 Craighead. Mrs. Gray's Collection. 



Ampyx cf. scanicus (Angelin). 24. 



1*;. Pygidium, showing broad obtuse axis and faintly segmented lateral lobes, x 2. Shalloch 

 Mill. Mrs. Gray's Collection. 



