140 ECHINUS. Class VI. 



the above ; but I cannot, either from descrip- 

 tion or print, determine whether it be the young, 

 or distinct. Vide Nat. Hist. Comzvall, p. 278. 

 tab. xxviii. Jig. 26. 



4. CiDARIS. Gm. Lin. 3174. Mem. Wern. Soc. 359- 



* EcH. hemispheeric, depressed, with five linear 

 flexuous ambulacra or avenues, the intervening 

 compartments alternately bifarious. 



Var. a. Gm. Lin. 3174- a. ? Soiv. Br. Misc. tah. 44. 



* This variety is covered with spines of very 

 different sizes, the largest are flat, and in length 

 nearly equal to the diameter of the body, blunt 

 at the ends, and some of them partly spatulate. 



Found on the coast of Shetland. 



5. Placenta. Gm.Lin.2\g5. Mem. Wem. Soc. 5bQ. 



* EcH. subconic, of ten compartments, each 

 alternate, one narrower ; five plain avenues de- 

 hiscent or gaping at the ends. 



From the isle of Fulah ; rare, 



6. PuLviKu- * EcH. of a form nearly hemisphasric, some- 

 what depressed, with five linear truncated ave- 



