294 



COMPARATIVE ANATOMY 



CHAP. 



- 



K3&& 



Fici. -'30. Schizaster lacu- 

 nosus ? from the 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 

 interarnbulacrum ; 5, the right 

 posterior ambulacrum ; 6, the 

 unpaired posterior interambula- 

 crum ; 7, anal region. 



FIG. 237. Palaeopneustes 

 Murray! (after Agassiz), 

 from the oral side. 1, The 

 anterior ambulacrum ; 2, 3, 

 the anterior right and the 

 posterior right ambulacra ; 

 4, peristome ; 5, anal region. 



