PLATE II. 



Fig. Page. 



Trinucleus subradiatus, sp. nov. 12. 



1. Head-shield (imperfect), showing- sharply carinated glabella with two pairs of short broad 



furrows, cheeks with "ocular tubercle " and eye-line, fringe with two marginal concentric 

 rows of large pits and inner radial rows of smaller pits. X 3. Dow Hill. Mrs. Gray's 

 Collection. 

 1 a. Side view of same, showing shape and elevation of glabella, x 3. 



2. Portion of fringe, showing contour and genal spine. X 2. Dow Hill. Mrs. Gray's Collection. 



3. Portion of head-shield, showing neck segment and nuchal spine. x 3. Dow Hill. 



Mrs. Gray's Collection. 



4. Head-shield, showing nuchal spine, etc. x 3. Dow Hill. Mrs. Gray's Collection. 



5. Cast of head-shield, showing carinated glabella, radial rows of small pits on inner portion of 



fringe, and general shape of fringe, x 4. Dow Hill. Mrs. Gray's Collection. 



6. Cast of fringe, showing marginal concentric and inner radial rows of pits, inward 



curvature, and backward prolongation of genal angle. X 3. Dow Hill. Woodwardian 

 Museum. 



Trinucleus, sp. (a). 14. 



7. Portion of head-shield, showing frontal lobe of glabella with surface coarsely reticulated, 



cheek with similar ornamentation and tubercle, and fragment of fringe, x 3. Shalloch 

 Mill. Mrs. Gray's Collection. 

 7 a. Genal portion of fringe and spine, x 2. Shalloch Mill. Mrs. Gray's Collection. 



7 b. Genal portion of fringe and spine, with part of cheek attached, x 2. Shalloch Mill. 



Mrs. Gray's Collection. (Figured by Nicholson and Etheridge, 'Mon. Silur. Foss. 

 Girvan,' fasc. ii, pi. xiv, fig. 2.) 



Trinucleus, sp. (b). 14. 



8. Head-shield, nearly perfect, showing neck of glabella formed of one lobe, and fringe with 



only two rows of pits, x 2. Whitehouse. Mrs. Gray's Collection. 



8 a. Head-shield with similar features, x 2. Shalloch Mill. Mrs. Gray's Collection. 



Trinucleus, sp. (c). 15. 



9. Pygidium with numerous rings on axis, x 2. Shalloch Mill. Mrs. Gray's Collection. 



(Figured by Nicholson and Etheridge, ' Mon. Silur. Foss. Girvan,' fasc. ii, pi. xiv, 

 fig. 4.) 



Trinucleus, sp. (d). 15. 



10. Head-shield, showing glabella with elongated frontal lobe, short neck, and numerous small 



pits on fringe. X 5. Whitehouse. Mrs. Gray's Collection. 

 10 a. Pygidium, showing pits between rings on axis. X 6. Whitehouse. Mrs. Gray's 

 Collection. 



Trinucleus, sp. (/). 16. 



11. Pygidium with broad rounded axis, x 3. Shalloch Mill. Mrs. Gray's Collection. 



Harpes flanagani, Portlock. 8. 



12. Horse-shoe limb, showing single row of large pits inside narrow border, x 3. Ardmillan. 



Mrs. Gray's Collection. 

 12 a. Portion of limb and cheek bearing eye and showing radiating rows of minute punctures. 

 x 4. Dow Hill. Mrs. Gray's Collection. 



Harpes, sp. («). 9. 



13. Portion of fringe, showing strong rounded border and single row of pits inside it. x 2. 



Shalloch Mill. Mrs. Gray's Collection. 



Harpes, sp. (b). 9. 



14. Horseshoe limb, nearly complete, showing narrow smooth rim and irregularly arranged 



minute pits on surface of limb, and fine radiating lines of punctures on cheeks, x 3. 

 Bargany Pond Burn. Mrs. Gray's Collection. 



