294 



COMPARATIVE ANATOMY 



Fio. 230. — Schizaster lacu- 

 nosus ? from tlie apical side 

 (original). The spines, and the 

 protuberances on which they 

 stand, are not depicted. 1, The 

 anterior unpaired ambulacrum ; 

 •2, the right anterior ambulacrum ; 

 3, fascicle ; 4, the right posterior 

 interambulacrum ; 5, the right 

 posterior ambulacrum ; 6, the 

 unpaired posterior interambula- 

 crum ; 7, anal region. 



Fi(i. 237.— Palaeopneustes 

 Murrayi (after Agassiz), 

 from the oral side. 1, The 

 anterior ambulacrum ; 2, 3, 

 ' riivtim ^''® anterior right and the 

 ' 'Ilvir posterior right ambulacra; 

 4, peristome ; 5, anal region. 



