PLATE 73. 
1-5. Urechinus giganteus A. Ag.; Station 3431. 
. Actinal system and surrounding plates of specimen 80 mm, in length, showing resorp- 
tion of miliaries in the posterior ambulacra. 
. Part of test of specimen 80 mm. in length, facing the right posterior interambulacrum, 
showing resorption of tubercles. 
. Part of test of same specimen, near ambitus, facing the right anterior ambulacrum. 
. The third plate from the actinostome of the left posterior interambulacrum, to show 
resorption of tubercles. 
. Anal system of same. 
