302 THE VOYAGE OF H.M.S. CHALLENGER. 



PLATE XXX. 



Urechinus naresianus, A. Ag. (figs. 1-24), p. 146. 



Fio-. 1. Young specimen, measuring 27 mm., seen from the abactinal side, 

 „ 2. Same, seen in profile. 

 „ 3. Same, seen from the actinal side. 



4. Somewhat younger specimen, measuring 18 mm., seen from the abactinal side. 

 „ 5. Same, seen in profile. 

 „ 6. Same, seen facing the anal extremity. 

 „ 7. Another specimen, measuring 16 mm., differing somewhat in outline, seen from 



the abactinal side. 

 „ 8. Younger specimen than fig. 4, measuring 15 mm., seen from the abactinal side. 

 ,, 9. Same, seen in profile. 

 ,, 10. Same, seen from the actinal side. 



„ 11. Still younger specimen, measuring only 13 mm., seen from the abactinal side. 

 ,, 12. Same, seen from the actinal side. 

 ,, 13. Same, seen in profile. 



14. Exterior view of actinostome and surrounding plates of specimen measuring 

 46 mm. 

 ,, 15. Interior view of same. 



„ 16. Abactinal system and surrounding plates of specimen measuring 46 mm. 

 „ 17. Interior view of apical system and sm-rounding plates of specimen measuring 



46 mm. 

 „ 18. Interior view of anal system and portion of adjoining ambulacral areas. 

 „ 19. Anal system and indistinct subanal fasciole. 



„ 20. Magnified primary spine, from the edge of ambitus of specimen measuring 40 mm. 

 ,, 21. Miliary spine of same. 



22. Trifid elongate pedicellaria, with slender-stemmed articulation. 

 „ 23. Club-shaped pedicellaria, wdth heavy-stemmed articulation, seen in profile. 

 „ 24. Head of same, seen from above. 



PLATE XXX^. 



Urechinus naresianus, A. Ag. (figs. 1-14), p. 146. 

 Fig. 1. Conical individual, seen from the abactinal side (f ). 



2. Same, seen from the actinal side. 



3. Same, seen in profile. 



