SYSTEMATIC ( I.ASSIFK'ATJON OF ECHINI 



23] 



Si 



o 





3 ° 





•C! O 



tS) 



o 







Palacechinus elegans. 



Maccoya burlingtonensis. 



Lovenechinus missouriensis. 



Oligoporus danae. 



Nl 







Melonechinus springer! . 



JNIelonechinus indianensis. 







Mcloncchinus multiporus. 



«^ CO', '.to 







GO 







Melonechinus giganteus below 

 the heavy line, and Melon- 

 echinus keepingi above the 

 heavy line. 



0-. -fc" CO ?^ 



