Plate 30. 



A valve 0.78 mm. 

 A valve 0.77 mm. 



7. A valve 0.41 mm. 



8. A valve 0.47 mm. 



10. A valve 0.12 mm. 



11. A valve 0.14 mm. 



12. A valve 0.46 mm. 



13. A valve 0.44 mm. 



14. A valve 0.31 mm. 



15. A valve 0.27 mm. 



16. A valve 0.9 mm. 



1-16. Colobocentrotus Mertensii Brandt. 



1-1 6. Valves of pedicellarise. 



1. A valve 0.38 mm. > Ophicephalous pedicellaria, interior view near the teeth. 



2. A valve 0.35 mm. ' Ophicephalous pedicellaria, exterior view, near the teeth. 



3. A valve 0.81 mm. "| Tridentate pedicellaria, exterior view, close to the actinal system 



from the odd anterior ambulacrum. 



Tridentate pedicellaria, interior view of the same pedicellaria as 3. 



Tridentate pedicellaria, profile, interior view of the same as 3. 

 6. A valve 0.54 mm. ] Tridentate pedicellaria, exterior view, midway between the ambitus 



and the actinal system, from the left posterior ambulacrum. 



Tridentate pedicellaria, interior view, from the left posterior am- 

 bulacrum. 



Tridentate pedicellaria, close to the ambitus, from the right an- 

 terior ambulacrum. 

 9. A valve 0.48 mm. Ophicephalous pedicellaria, exterior view, close to the ambitus, 

 from the right anterior ambulacrum. 



Triphyllous pedicellaria, exterior view, midway between the actinal 

 system and the ambitus, from the left anterior ambulacrum. 



Triphyllous pedicellaria, profile, same pedicellaria as 10. 



Ophicephalous pedicellaria, interior view close to the ambitus, 

 from the right anterior interambulacrum. 



Ophicephalous pedicellaria, exterior view of same pedicellaria as 

 12. 



Ophicephalous pedicellaria, interior view midway between the am- 

 bitus and the abactinal system, from the left posterior interam- 

 bulacrum. * 



Ophicephalous pedicellaria, exterior view of the same pedicellaria 

 as 14. 



Triphyllous pedicellaria, exterior view, close to the ocular plate, 

 from the right anterior ambulacrum. 

 From a specimen measuring 70 mm. in diameter, with spines. 

 Bonin Ids., N. P. Ex. Ex., Dr. Wm. Stimpson Coll. 



^, 



