EXPLANATION OF PLATES 



Plate 48 



Histocidaris magnified, new species. Side view. Natural size 



Plate 49 



Histocidaris magnified, new species. Seen from the oral side. Natural size 



Plate 50 



Histocidaris acutispina. Natural size 



Fig. 1. Seen from the oral side. 

 2. Seen from the aboral side. 



Plate 51 



Histocidaris, species. Natural size 

 Fig. 1. Side view. 



2. Seen from oraJ side. 



Plate 52 



All figures natural size 



Fig. 1. Histocidaris elegans, naked test, side view. 



2. Histocidaris acutispina; primary spines. 



3. Prionocidaris bispinosa; primary spines. 



Plate 53 



Prionocidaris baculosa, var. annulifera; oral side. Natural size 



Plate 54 



Prionocidaris baculosa, var. annulifera; aboral side. Natural size 



Plate 55 

 Goniocidaris (Discocidaris) peltata, new species; aboral side. Natural size 



Plate 56 

 Goniocidaris (Discocidaris) peltata, new species; oral side. Natural size 



Plate 57 

 All figures natural size 



Fig. 1. Goniocidaris (Cyrtocidaris) tenuispina, new species; aboral side. 



2. Same specimen; oral side. 



3. Goniocidaris (Cyrtocidaris) tenuispina, new species, var. tuberculata, 



new variety; aboral side. 



307 



