PLATE 29. 
1-14. Micropetalon purpureum A. Aacassiz and H. L. Crark. 
1.— Actinal side of a dry specimen, 17 mm. long including spines, from the Hawaiian Islands. 
2.— The same from the abactinal side. 
3.— The same in profile, facing left anterior interambulacrum and left posterior interambulacrum. 
4.— Exterior view of abactinal system, denuded, showing the madreporite and genital pores. 
5.— The same as Figure 4, from the interior. 
6.— Odd anterior ambulacrum, showing pores and arrangement of primary tubercles and milliaries. 
7.— Seventh plate from the edge of actinostome, in left anterior interambulacrum. 
8.— Plate from posterior interambulacrum, abactinal side near the apex. 
9.— Peripodium, at the edge of actinostome in odd anterior ambulacrum. 
10.— Fifth peripodia from the actinostome. 
11.— One of the peripodia in the ambitus. 
12.— Peripodium near the ocular plate. 
13.— Sphaeridium, first from edge of actinostome, in odd anterior ambulacrum. 
14.— Second sphaeridia, from same ambulacrum as preceding. 
