FIDDLE HEART-UIICHIN. 



189 



twelve and fourteen. The pores of the central ambulacra 

 are evident, closely placed in two single rows, distant, 

 and nearly opposite. The anal impression is circular ; the 

 sub-anal, ample and reniform. On the under surface 

 the post-oral space is long and narrow, the smooth im- 

 perforate avenues wide, and the oral ambulacra somewhat 

 triangular. 



