PLATE IV. 



Fig. Page. 



Dionide lapworthi, Etheridge, jun., and Nicholson. 25. 



1. Complete individual (flattened by pressure), showing all the specific characters. X 2. 



Whitehouse. Mrs. Gray's Collection. (Figured by Nicholson and Etheridge, 'Mod. 

 Silur. Foss. Girvan,' fasc. iii, pi. xx, fig. 1.) 



2. Thorax and pygidiuni. x 3. Whitehouse. Mrs. Gray's Collection. (Figured by 



Nicholson and Etheridge, op. cit., pi. xx, fig. 3.) 



Dionide richardsoni, sp. nov. 26. 



3. Complete individual (except for points of genal spines). The apparent strong constriction 



of the glabella is due to imperfect preservation, x 2. Whitehouse Bay. Mrs. Gray's 

 Collection. 



4. Nearly perfect individual, showing swollen bases of pleurae and ornamentation. Glabella 



crushed. X 2|. Thraive Glen. Mrs. Gray's Collection. 



5. Ditto, showing cast of hypostome. x 3. Thraive Glen. Mrs. Gray's Collection. 



6. Imperfect specimen, showing much elongated genal spine. X 2. Thraive Glen. Mrs. 



Gray's Collection. 



7. Ditto. X 4. Drummock Quarry. Mrs. Gray's Collection. (Figured by Nicholson and 



Etheridge, op. cit., pi. vii, fig. 3, as Phacops truncato-caudatus, Portlock.) 



8. Portion of head-shield, showing well-preserved glabella with base of median spine, x 3. 



Thraive Glen. Mrs. Gray's Collection. 



Apatokephalus, sp. 30. 



9. Nearly perfect pygidiuni. x 5. Balclatchie. Mrs. Gray's Collection. 



Triarthrus becki (Green), var. 28. 



10. Glabella and fixed cheeks, showing furrows and eye-lobes, x 5. Balclatchie. Mrs. Gray's 

 Collection. 



Telephus fractus, Barrande. 



11. Imperfect specimen, showing neck-spine and eye-lobe. X 3. Whitehouse Bay. Mrs. Gray's 

 Collection. 



Shumardia scotica, sp. nov. 42. 



12. Well-preserved head-shield, x 9. Whitehouse. Mrs. Gray's Collection. 



Salteria primaeva, Wyv. Thomson. 43. 



13. Head-shield with three thoracic segments attached, x 3. Balclatchie. Mrs. Gray's 



Collection. 



14. Crushed specimen, showing base of head-shield, thorax, and pygidiuni. x 4. Balclatchie. 



Mrs. Gray's Collection. 



