X' 



k ,$ V EXPLANATION OF PLATE XVI. 



T 



(All figures after Clark.) 



HEMIASTER STELLA (Morton), P- 300 



1-4. Dorsal, ventral, lateral and posterior views of a complete 

 individual. 



I'inccntoivn limesand. 



HEMIASTER UNGULA (Morton), p. 301 



5-8. Dorsal, ventral, lateral and posterior views of a complete 



individual. 

 9. Portion of the petaloid region of the right antero-lateral 



ambulacrum, much enlarged. 

 10. Portion of the petaloid region of the anterior ambulacrum, 



much enlarged, 

 n. Apical disk, enlarged. 



Vinccntozvn liincsand. 



$12 



