246 Prof. F. J. Bell on Echinoderms from 
Pterasteridx. 
15. Retaster cribrosus, v. Martens. 
Zanzibar, shore, and Wasin, 7 fath. 
Echinasteride. 
16. Mithrodia clavigera, Lamk. 
Wasin, 10 fath. 
“17. Echinaster purpureus, Gray. 
Wasin. 
OPHIUROIDEA. 
It is very curious that there should be only three Ophiu- 
roids: of these one is of great rarity ; it was described from 
specimens collected by H.M.S. ‘ Alert.’ 
18. Ophioplocus imbricatus, M. Tr. 
Zanzibar. 
19. Fragments of what appeared to be Ophiomyzxa australis, 
Liitken. 
20. Ophioteresis elegans, Bell. 
Found nestling in the arms of a many-armed Actinometra 
from Zanzibar. 
ECHINOIDEA, 
Cidarida. 
21. Cidaris metularia, Lamk. 
Zanzibar ; Wasin, 7 fath. 
22. Leiocidaris verticillata, Lamk. 
Wasin, 10 fath. 
23. Letocidaris baculosa, Lamk. 
Wasin, 10 fath. 
Diadematida. 
24, Diadema saxatile, L. 
Wasin, 10 fath. 
