PLATE 13. 
1-6. Echinonéus cyclostomus Leske. t 
1.— Interior view of actinal side, from alcoholic specimen, measuring 4.40 mm. long. Makem 
Paumotu_ Islands. ; : 7 
2.— Actinal side seen from interior. Test measuring 27 mm. long. Makemo Island. 
3.— Odd anterior ambulacrum with part of the right and left anterior interradial plates, : 
actinal system, seen from interior. , ¥ ; 
4.— Interior view of median interambulacral suture in right posterier interambulac: 
stome, showing overlapping of plates. 
5.— Odd anterior ambulacrum, near ambitus, actinal side, seen from interior. 
6.— Ocular and abactinal ambulacral plates of odd anterior ambulacrum, interior v 
Figures 3-6 from a dry specimen, measuring 37 mm. long. Mauritius. 
The enlargement is identical in Figures 3, 5, 6. 
