PLATE XIX^ 



Lovenia elongata, /. 1-4- 



1. Denuded, seen from above. 



2. Same, from the actinal side. 



3. Larger specimen, covered with spines, from the abactinal side. 



4. The same, seen from the actinal side. 



Spatangus purpureua, /. 5, 6. 



5. Seen from the abactinal pole. 



6. Seen from the actinal side. 



{Figs. 1-4 natural size; 5, 6, three fourths natural size.) 



