PLATE XXXI. 



Schinaracbnius parma. 



1. Seen from above, with spines and suckers expanded. Nat. size. 



2. Actinal floor removed to show course of alimentary canal and of the principal vessel 



sending branches to the water-tubes both in the ambulacral and interambulacral 

 spaces. 



3. Part of edge of test of youug specimen, with suckers and pedicellarise ; measuring G"""- 



4. Part of ambulacral petal of young specimen measuring 6°"°- 



5. Ambulacral tubes of petaloid jiortion of adult specimen. 



6. Ambulacral suckers of petaloid portion of same specimen as Fig. 3. 



V, 8, 9. Different views of ambulacral suckers from petaloid portion of adult specimen. 



10. Water-tubes from the median ambulacral part of the petals. 



11. Water-tubes from the interambulacral space. 



12. Terminal disk of the suckers of the ambulacra from the petaloid portion. 



1.3. Single ambulacral sucker of petal to show the mode of junction of the two parts of the 

 suckers leading from the ambulacral pores. 



14. Part of the ambulacral edge of the mouth showing the simple suckers of the buccal 



rosette (from young specimen. Fig. 3). 



15. The two large buccal tentacles, somewhat more magnified, same as Fig. 14. 



16. Spine of edge of test of Fig. 3, magnified. 



17. One of the pedicellaria; of the edge of the test of Fig. 3. 



