PLATE XI/. 



Echinantbus rosaceus, / 1-lS. 



1. Young specimen, from abactinal side, with spines, nat. size. 



2. Part of petaloiJ ambulacrum of same magnified, sliowing the tentacles provided with suckers. 



3. Portion of edge of test of same, showing the tentacles passing through the test outside of the regu- 



lar poriferous zone. 



4. Part of test of same, denuded, magnified. 



5. Magnified portion of petaloid ambulacrum, pores connected by furrows. 



6. First kind of tridactyle pedicellaria, with shaft, magnified. 



7. Same closely contracted. 



8. Terminal part of jaw of pedicellaria. 



9. Pedicellaria closed, seen from above, magnified. 



10. Second kind of globular pedicellaria carried upon a slender shaft and long contractile stem, mag- 



nified. 



11. Younger stage of same. 



12. Young fan-shaped articulated spine, magnified greatly. 



13. Somewhat younger spine. 



14. Spine having all features of the spines of large, full-grown specimens, magnified. 



15. Section of edge of a specimen, somewhat older, showing commencement of the double-chambereil 



walls, ^ nat. size. 

 1«. Magnified p.irt of interambulacral part of test of same, showing the ambulacral pores discovered 



by Miiller. 

 17. Portion of petaloid ambulacrum of adult specimen, nat. size. 

 IS. Magnified portion of same, to show the lobed tentacles of the petaloid ambulacra. 



SpataUgus purpureus, / 19 -S2. 



19. Magnified abactinal part of test of fig. 20. 



20. Young specimen, from abactinal pole, | nat. size. 



21. Same from actinal side. 



22. Same seen in profile. 



Agassizia excentrica, /. 23, 2f. 



23. Same from abactinal pole, nat. size. 



24. Seen in profile, nat. size. 



Clypeaster subdepressus, f. S5. 



25. Part of the poriferous zone of the actinal side of specimen measuring 25.4""- in diam., magnified. 



