PiATE XVII. 



The Calycinal System of Spatangidae. 



P. 74. 



Pig. 197. The calvx of a sjjeciraen of Echinocardium Havescens O. F. M., raeasiiring 3,5 : 3 mm. 



Fig-. 198. The same, at 7 ; 6 mm. 



Fig. 199. The same, at 8 : 6 mm. 



Fig. 200. The same, at 9 : 7,5 mm. 



Fig. 201. The same, at 9,5 : 8 mm. 



Fig. 202. The same, at 10,5 : 9 ram. 



Fig. 203. The same, at 10,5 : 9 mm. 



Fig. 204. The same, at 12 : 10 mm. 



Fig. 205. The same, at 14,5 : 12 ram. 



Fig. 206. The same, at 30 ; 26 mra. 



Fig. 207. The same, at 36 : 32 rara. 



Fig. 208. The calyx of Palieotropiis Josephiiuie Lov. 



